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------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ C H 4 -- -- -- -- B o d y -- -- -- -- Copyright (C) 1992-2009, Free Software Foundation, Inc. -- -- -- -- GNAT is free software; you can redistribute it and/or modify it under -- -- terms of the GNU General Public License as published by the Free Soft- -- -- ware Foundation; either version 3, or (at your option) any later ver- -- -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- -- for more details. You should have received a copy of the GNU General -- -- Public License distributed with GNAT; see file COPYING3. If not, go to -- -- http://www.gnu.org/licenses for a complete copy of the license. -- -- -- -- GNAT was originally developed by the GNAT team at New York University. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ with Atree; use Atree; with Debug; use Debug; with Einfo; use Einfo; with Elists; use Elists; with Errout; use Errout; with Exp_Util; use Exp_Util; with Fname; use Fname; with Itypes; use Itypes; with Lib; use Lib; with Lib.Xref; use Lib.Xref; with Namet; use Namet; with Namet.Sp; use Namet.Sp; with Nlists; use Nlists; with Nmake; use Nmake; with Opt; use Opt; with Output; use Output; with Restrict; use Restrict; with Rident; use Rident; with Sem; use Sem; with Sem_Aux; use Sem_Aux; with Sem_Cat; use Sem_Cat; with Sem_Ch3; use Sem_Ch3; with Sem_Ch6; use Sem_Ch6; with Sem_Ch8; use Sem_Ch8; with Sem_SCIL; use Sem_SCIL; with Sem_Disp; use Sem_Disp; with Sem_Dist; use Sem_Dist; with Sem_Eval; use Sem_Eval; with Sem_Res; use Sem_Res; with Sem_Util; use Sem_Util; with Sem_Type; use Sem_Type; with Stand; use Stand; with Sinfo; use Sinfo; with Snames; use Snames; with Tbuild; use Tbuild; package body Sem_Ch4 is ----------------------- -- Local Subprograms -- ----------------------- procedure Analyze_Concatenation_Rest (N : Node_Id); -- Does the "rest" of the work of Analyze_Concatenation, after the left -- operand has been analyzed. See Analyze_Concatenation for details. procedure Analyze_Expression (N : Node_Id); -- For expressions that are not names, this is just a call to analyze. -- If the expression is a name, it may be a call to a parameterless -- function, and if so must be converted into an explicit call node -- and analyzed as such. This deproceduring must be done during the first -- pass of overload resolution, because otherwise a procedure call with -- overloaded actuals may fail to resolve. procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id); -- Analyze a call of the form "+"(x, y), etc. The prefix of the call -- is an operator name or an expanded name whose selector is an operator -- name, and one possible interpretation is as a predefined operator. procedure Analyze_Overloaded_Selected_Component (N : Node_Id); -- If the prefix of a selected_component is overloaded, the proper -- interpretation that yields a record type with the proper selector -- name must be selected. procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id); -- Procedure to analyze a user defined binary operator, which is resolved -- like a function, but instead of a list of actuals it is presented -- with the left and right operands of an operator node. procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id); -- Procedure to analyze a user defined unary operator, which is resolved -- like a function, but instead of a list of actuals, it is presented with -- the operand of the operator node. procedure Ambiguous_Operands (N : Node_Id); -- for equality, membership, and comparison operators with overloaded -- arguments, list possible interpretations. procedure Analyze_One_Call (N : Node_Id; Nam : Entity_Id; Report : Boolean; Success : out Boolean; Skip_First : Boolean := False); -- Check one interpretation of an overloaded subprogram name for -- compatibility with the types of the actuals in a call. If there is a -- single interpretation which does not match, post error if Report is -- set to True. -- -- Nam is the entity that provides the formals against which the actuals -- are checked. Nam is either the name of a subprogram, or the internal -- subprogram type constructed for an access_to_subprogram. If the actuals -- are compatible with Nam, then Nam is added to the list of candidate -- interpretations for N, and Success is set to True. -- -- The flag Skip_First is used when analyzing a call that was rewritten -- from object notation. In this case the first actual may have to receive -- an explicit dereference, depending on the first formal of the operation -- being called. The caller will have verified that the object is legal -- for the call. If the remaining parameters match, the first parameter -- will rewritten as a dereference if needed, prior to completing analysis. procedure Check_Misspelled_Selector (Prefix : Entity_Id; Sel : Node_Id); -- Give possible misspelling diagnostic if Sel is likely to be a mis- -- spelling of one of the selectors of the Prefix. This is called by -- Analyze_Selected_Component after producing an invalid selector error -- message. function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean; -- Verify that type T is declared in scope S. Used to find interpretations -- for operators given by expanded names. This is abstracted as a separate -- function to handle extensions to System, where S is System, but T is -- declared in the extension. procedure Find_Arithmetic_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id); -- L and R are the operands of an arithmetic operator. Find -- consistent pairs of interpretations for L and R that have a -- numeric type consistent with the semantics of the operator. procedure Find_Comparison_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id); -- L and R are operands of a comparison operator. Find consistent -- pairs of interpretations for L and R. procedure Find_Concatenation_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id); -- For the four varieties of concatenation procedure Find_Equality_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id); -- Ditto for equality operators procedure Find_Boolean_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id); -- Ditto for binary logical operations procedure Find_Negation_Types (R : Node_Id; Op_Id : Entity_Id; N : Node_Id); -- Find consistent interpretation for operand of negation operator procedure Find_Non_Universal_Interpretations (N : Node_Id; R : Node_Id; Op_Id : Entity_Id; T1 : Entity_Id); -- For equality and comparison operators, the result is always boolean, -- and the legality of the operation is determined from the visibility -- of the operand types. If one of the operands has a universal interpre- -- tation, the legality check uses some compatible non-universal -- interpretation of the other operand. N can be an operator node, or -- a function call whose name is an operator designator. function Find_Primitive_Operation (N : Node_Id) return Boolean; -- Find candidate interpretations for the name Obj.Proc when it appears -- in a subprogram renaming declaration. procedure Find_Unary_Types (R : Node_Id; Op_Id : Entity_Id; N : Node_Id); -- Unary arithmetic types: plus, minus, abs procedure Check_Arithmetic_Pair (T1, T2 : Entity_Id; Op_Id : Entity_Id; N : Node_Id); -- Subsidiary procedure to Find_Arithmetic_Types. T1 and T2 are valid -- types for left and right operand. Determine whether they constitute -- a valid pair for the given operator, and record the corresponding -- interpretation of the operator node. The node N may be an operator -- node (the usual case) or a function call whose prefix is an operator -- designator. In both cases Op_Id is the operator name itself. procedure Diagnose_Call (N : Node_Id; Nam : Node_Id); -- Give detailed information on overloaded call where none of the -- interpretations match. N is the call node, Nam the designator for -- the overloaded entity being called. function Junk_Operand (N : Node_Id) return Boolean; -- Test for an operand that is an inappropriate entity (e.g. a package -- name or a label). If so, issue an error message and return True. If -- the operand is not an inappropriate entity kind, return False. procedure Operator_Check (N : Node_Id); -- Verify that an operator has received some valid interpretation. If none -- was found, determine whether a use clause would make the operation -- legal. The variable Candidate_Type (defined in Sem_Type) is set for -- every type compatible with the operator, even if the operator for the -- type is not directly visible. The routine uses this type to emit a more -- informative message. function Process_Implicit_Dereference_Prefix (E : Entity_Id; P : Node_Id) return Entity_Id; -- Called when P is the prefix of an implicit dereference, denoting an -- object E. The function returns the designated type of the prefix, taking -- into account that the designated type of an anonymous access type may be -- a limited view, when the non-limited view is visible. -- If in semantics only mode (-gnatc or generic), the function also records -- that the prefix is a reference to E, if any. Normally, such a reference -- is generated only when the implicit dereference is expanded into an -- explicit one, but for consistency we must generate the reference when -- expansion is disabled as well. procedure Remove_Abstract_Operations (N : Node_Id); -- Ada 2005: implementation of AI-310. An abstract non-dispatching -- operation is not a candidate interpretation. function Try_Indexed_Call (N : Node_Id; Nam : Entity_Id; Typ : Entity_Id; Skip_First : Boolean) return Boolean; -- If a function has defaults for all its actuals, a call to it may in fact -- be an indexing on the result of the call. Try_Indexed_Call attempts the -- interpretation as an indexing, prior to analysis as a call. If both are -- possible, the node is overloaded with both interpretations (same symbol -- but two different types). If the call is written in prefix form, the -- prefix becomes the first parameter in the call, and only the remaining -- actuals must be checked for the presence of defaults. function Try_Indirect_Call (N : Node_Id; Nam : Entity_Id; Typ : Entity_Id) return Boolean; -- Similarly, a function F that needs no actuals can return an access to a -- subprogram, and the call F (X) interpreted as F.all (X). In this case -- the call may be overloaded with both interpretations. function Try_Object_Operation (N : Node_Id) return Boolean; -- Ada 2005 (AI-252): Support the object.operation notation procedure wpo (T : Entity_Id); pragma Warnings (Off, wpo); -- Used for debugging: obtain list of primitive operations even if -- type is not frozen and dispatch table is not built yet. ------------------------ -- Ambiguous_Operands -- ------------------------ procedure Ambiguous_Operands (N : Node_Id) is procedure List_Operand_Interps (Opnd : Node_Id); -------------------------- -- List_Operand_Interps -- -------------------------- procedure List_Operand_Interps (Opnd : Node_Id) is Nam : Node_Id; Err : Node_Id := N; begin if Is_Overloaded (Opnd) then if Nkind (Opnd) in N_Op then Nam := Opnd; elsif Nkind (Opnd) = N_Function_Call then Nam := Name (Opnd); else return; end if; else return; end if; if Opnd = Left_Opnd (N) then Error_Msg_N ("\left operand has the following interpretations", N); else Error_Msg_N ("\right operand has the following interpretations", N); Err := Opnd; end if; List_Interps (Nam, Err); end List_Operand_Interps; -- Start of processing for Ambiguous_Operands begin if Nkind (N) in N_Membership_Test then Error_Msg_N ("ambiguous operands for membership", N); elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) then Error_Msg_N ("ambiguous operands for equality", N); else Error_Msg_N ("ambiguous operands for comparison", N); end if; if All_Errors_Mode then List_Operand_Interps (Left_Opnd (N)); List_Operand_Interps (Right_Opnd (N)); else Error_Msg_N ("\use -gnatf switch for details", N); end if; end Ambiguous_Operands; ----------------------- -- Analyze_Aggregate -- ----------------------- -- Most of the analysis of Aggregates requires that the type be known, -- and is therefore put off until resolution. procedure Analyze_Aggregate (N : Node_Id) is begin if No (Etype (N)) then Set_Etype (N, Any_Composite); end if; end Analyze_Aggregate; ----------------------- -- Analyze_Allocator -- ----------------------- procedure Analyze_Allocator (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); Sav_Errs : constant Nat := Serious_Errors_Detected; E : Node_Id := Expression (N); Acc_Type : Entity_Id; Type_Id : Entity_Id; begin -- In accordance with H.4(7), the No_Allocators restriction only applies -- to user-written allocators. if Comes_From_Source (N) then Check_Restriction (No_Allocators, N); end if; if Nkind (E) = N_Qualified_Expression then Acc_Type := Create_Itype (E_Allocator_Type, N); Set_Etype (Acc_Type, Acc_Type); Find_Type (Subtype_Mark (E)); -- Analyze the qualified expression, and apply the name resolution -- rule given in 4.7 (3). Analyze (E); Type_Id := Etype (E); Set_Directly_Designated_Type (Acc_Type, Type_Id); Resolve (Expression (E), Type_Id); if Is_Limited_Type (Type_Id) and then Comes_From_Source (N) and then not In_Instance_Body then if not OK_For_Limited_Init (Type_Id, Expression (E)) then Error_Msg_N ("initialization not allowed for limited types", N); Explain_Limited_Type (Type_Id, N); end if; end if; -- A qualified expression requires an exact match of the type, -- class-wide matching is not allowed. -- if Is_Class_Wide_Type (Type_Id) -- and then Base_Type -- (Etype (Expression (E))) /= Base_Type (Type_Id) -- then -- Wrong_Type (Expression (E), Type_Id); -- end if; Check_Non_Static_Context (Expression (E)); -- We don't analyze the qualified expression itself because it's -- part of the allocator Set_Etype (E, Type_Id); -- Case where allocator has a subtype indication else declare Def_Id : Entity_Id; Base_Typ : Entity_Id; begin -- If the allocator includes a N_Subtype_Indication then a -- constraint is present, otherwise the node is a subtype mark. -- Introduce an explicit subtype declaration into the tree -- defining some anonymous subtype and rewrite the allocator to -- use this subtype rather than the subtype indication. -- It is important to introduce the explicit subtype declaration -- so that the bounds of the subtype indication are attached to -- the tree in case the allocator is inside a generic unit. if Nkind (E) = N_Subtype_Indication then -- A constraint is only allowed for a composite type in Ada -- 95. In Ada 83, a constraint is also allowed for an -- access-to-composite type, but the constraint is ignored. Find_Type (Subtype_Mark (E)); Base_Typ := Entity (Subtype_Mark (E)); if Is_Elementary_Type (Base_Typ) then if not (Ada_Version = Ada_83 and then Is_Access_Type (Base_Typ)) then Error_Msg_N ("constraint not allowed here", E); if Nkind (Constraint (E)) = N_Index_Or_Discriminant_Constraint then Error_Msg_N -- CODEFIX ("\if qualified expression was meant, " & "use apostrophe", Constraint (E)); end if; end if; -- Get rid of the bogus constraint: Rewrite (E, New_Copy_Tree (Subtype_Mark (E))); Analyze_Allocator (N); return; -- Ada 2005, AI-363: if the designated type has a constrained -- partial view, it cannot receive a discriminant constraint, -- and the allocated object is unconstrained. elsif Ada_Version >= Ada_05 and then Has_Constrained_Partial_View (Base_Typ) then Error_Msg_N ("constraint no allowed when type " & "has a constrained partial view", Constraint (E)); end if; if Expander_Active then Def_Id := Make_Defining_Identifier (Loc, New_Internal_Name ('S')); Insert_Action (E, Make_Subtype_Declaration (Loc, Defining_Identifier => Def_Id, Subtype_Indication => Relocate_Node (E))); if Sav_Errs /= Serious_Errors_Detected and then Nkind (Constraint (E)) = N_Index_Or_Discriminant_Constraint then Error_Msg_N -- CODEFIX ("if qualified expression was meant, " & "use apostrophe!", Constraint (E)); end if; E := New_Occurrence_Of (Def_Id, Loc); Rewrite (Expression (N), E); end if; end if; Type_Id := Process_Subtype (E, N); Acc_Type := Create_Itype (E_Allocator_Type, N); Set_Etype (Acc_Type, Acc_Type); Set_Directly_Designated_Type (Acc_Type, Type_Id); Check_Fully_Declared (Type_Id, N); -- Ada 2005 (AI-231): If the designated type is itself an access -- type that excludes null, its default initialization will -- be a null object, and we can insert an unconditional raise -- before the allocator. if Can_Never_Be_Null (Type_Id) then declare Not_Null_Check : constant Node_Id := Make_Raise_Constraint_Error (Sloc (E), Reason => CE_Null_Not_Allowed); begin if Expander_Active then Insert_Action (N, Not_Null_Check); Analyze (Not_Null_Check); else Error_Msg_N ("null value not allowed here?", E); end if; end; end if; -- Check restriction against dynamically allocated protected -- objects. Note that when limited aggregates are supported, -- a similar test should be applied to an allocator with a -- qualified expression ??? if Is_Protected_Type (Type_Id) then Check_Restriction (No_Protected_Type_Allocators, N); end if; -- Check for missing initialization. Skip this check if we already -- had errors on analyzing the allocator, since in that case these -- are probably cascaded errors. if Is_Indefinite_Subtype (Type_Id) and then Serious_Errors_Detected = Sav_Errs then if Is_Class_Wide_Type (Type_Id) then Error_Msg_N ("initialization required in class-wide allocation", N); else if Ada_Version < Ada_05 and then Is_Limited_Type (Type_Id) then Error_Msg_N ("unconstrained allocation not allowed", N); if Is_Array_Type (Type_Id) then Error_Msg_N ("\constraint with array bounds required", N); elsif Has_Unknown_Discriminants (Type_Id) then null; else pragma Assert (Has_Discriminants (Type_Id)); Error_Msg_N ("\constraint with discriminant values required", N); end if; -- Limited Ada 2005 and general non-limited case else Error_Msg_N ("uninitialized unconstrained allocation not allowed", N); if Is_Array_Type (Type_Id) then Error_Msg_N ("\qualified expression or constraint with " & "array bounds required", N); elsif Has_Unknown_Discriminants (Type_Id) then Error_Msg_N ("\qualified expression required", N); else pragma Assert (Has_Discriminants (Type_Id)); Error_Msg_N ("\qualified expression or constraint with " & "discriminant values required", N); end if; end if; end if; end if; end; end if; if Is_Abstract_Type (Type_Id) then Error_Msg_N ("cannot allocate abstract object", E); end if; if Has_Task (Designated_Type (Acc_Type)) then Check_Restriction (No_Tasking, N); Check_Restriction (Max_Tasks, N); Check_Restriction (No_Task_Allocators, N); end if; -- If the No_Streams restriction is set, check that the type of the -- object is not, and does not contain, any subtype derived from -- Ada.Streams.Root_Stream_Type. Note that we guard the call to -- Has_Stream just for efficiency reasons. There is no point in -- spending time on a Has_Stream check if the restriction is not set. if Restrictions.Set (No_Streams) then if Has_Stream (Designated_Type (Acc_Type)) then Check_Restriction (No_Streams, N); end if; end if; Set_Etype (N, Acc_Type); if not Is_Library_Level_Entity (Acc_Type) then Check_Restriction (No_Local_Allocators, N); end if; if Serious_Errors_Detected > Sav_Errs then Set_Error_Posted (N); Set_Etype (N, Any_Type); end if; end Analyze_Allocator; --------------------------- -- Analyze_Arithmetic_Op -- --------------------------- procedure Analyze_Arithmetic_Op (N : Node_Id) is L : constant Node_Id := Left_Opnd (N); R : constant Node_Id := Right_Opnd (N); Op_Id : Entity_Id; begin Candidate_Type := Empty; Analyze_Expression (L); Analyze_Expression (R); -- If the entity is already set, the node is the instantiation of a -- generic node with a non-local reference, or was manufactured by a -- call to Make_Op_xxx. In either case the entity is known to be valid, -- and we do not need to collect interpretations, instead we just get -- the single possible interpretation. Op_Id := Entity (N); if Present (Op_Id) then if Ekind (Op_Id) = E_Operator then if Nkind_In (N, N_Op_Divide, N_Op_Mod, N_Op_Multiply, N_Op_Rem) and then Treat_Fixed_As_Integer (N) then null; else Set_Etype (N, Any_Type); Find_Arithmetic_Types (L, R, Op_Id, N); end if; else Set_Etype (N, Any_Type); Add_One_Interp (N, Op_Id, Etype (Op_Id)); end if; -- Entity is not already set, so we do need to collect interpretations else Op_Id := Get_Name_Entity_Id (Chars (N)); Set_Etype (N, Any_Type); while Present (Op_Id) loop if Ekind (Op_Id) = E_Operator and then Present (Next_Entity (First_Entity (Op_Id))) then Find_Arithmetic_Types (L, R, Op_Id, N); -- The following may seem superfluous, because an operator cannot -- be generic, but this ignores the cleverness of the author of -- ACVC bc1013a. elsif Is_Overloadable (Op_Id) then Analyze_User_Defined_Binary_Op (N, Op_Id); end if; Op_Id := Homonym (Op_Id); end loop; end if; Operator_Check (N); end Analyze_Arithmetic_Op; ------------------ -- Analyze_Call -- ------------------ -- Function, procedure, and entry calls are checked here. The Name in -- the call may be overloaded. The actuals have been analyzed and may -- themselves be overloaded. On exit from this procedure, the node N -- may have zero, one or more interpretations. In the first case an -- error message is produced. In the last case, the node is flagged -- as overloaded and the interpretations are collected in All_Interp. -- If the name is an Access_To_Subprogram, it cannot be overloaded, but -- the type-checking is similar to that of other calls. procedure Analyze_Call (N : Node_Id) is Actuals : constant List_Id := Parameter_Associations (N); Nam : Node_Id; X : Interp_Index; It : Interp; Nam_Ent : Entity_Id; Success : Boolean := False; Deref : Boolean := False; -- Flag indicates whether an interpretation of the prefix is a -- parameterless call that returns an access_to_subprogram. function Name_Denotes_Function return Boolean; -- If the type of the name is an access to subprogram, this may be the -- type of a name, or the return type of the function being called. If -- the name is not an entity then it can denote a protected function. -- Until we distinguish Etype from Return_Type, we must use this routine -- to resolve the meaning of the name in the call. procedure No_Interpretation; -- Output error message when no valid interpretation exists --------------------------- -- Name_Denotes_Function -- --------------------------- function Name_Denotes_Function return Boolean is begin if Is_Entity_Name (Nam) then return Ekind (Entity (Nam)) = E_Function; elsif Nkind (Nam) = N_Selected_Component then return Ekind (Entity (Selector_Name (Nam))) = E_Function; else return False; end if; end Name_Denotes_Function; ----------------------- -- No_Interpretation -- ----------------------- procedure No_Interpretation is L : constant Boolean := Is_List_Member (N); K : constant Node_Kind := Nkind (Parent (N)); begin -- If the node is in a list whose parent is not an expression then it -- must be an attempted procedure call. if L and then K not in N_Subexpr then if Ekind (Entity (Nam)) = E_Generic_Procedure then Error_Msg_NE ("must instantiate generic procedure& before call", Nam, Entity (Nam)); else Error_Msg_N ("procedure or entry name expected", Nam); end if; -- Check for tasking cases where only an entry call will do elsif not L and then Nkind_In (K, N_Entry_Call_Alternative, N_Triggering_Alternative) then Error_Msg_N ("entry name expected", Nam); -- Otherwise give general error message else Error_Msg_N ("invalid prefix in call", Nam); end if; end No_Interpretation; -- Start of processing for Analyze_Call begin -- Initialize the type of the result of the call to the error type, -- which will be reset if the type is successfully resolved. Set_Etype (N, Any_Type); Nam := Name (N); if not Is_Overloaded (Nam) then -- Only one interpretation to check if Ekind (Etype (Nam)) = E_Subprogram_Type then Nam_Ent := Etype (Nam); -- If the prefix is an access_to_subprogram, this may be an indirect -- call. This is the case if the name in the call is not an entity -- name, or if it is a function name in the context of a procedure -- call. In this latter case, we have a call to a parameterless -- function that returns a pointer_to_procedure which is the entity -- being called. Finally, F (X) may be a call to a parameterless -- function that returns a pointer to a function with parameters. elsif Is_Access_Type (Etype (Nam)) and then Ekind (Designated_Type (Etype (Nam))) = E_Subprogram_Type and then (not Name_Denotes_Function or else Nkind (N) = N_Procedure_Call_Statement or else (Nkind (Parent (N)) /= N_Explicit_Dereference and then Is_Entity_Name (Nam) and then No (First_Formal (Entity (Nam))) and then Present (Actuals))) then Nam_Ent := Designated_Type (Etype (Nam)); Insert_Explicit_Dereference (Nam); -- Selected component case. Simple entry or protected operation, -- where the entry name is given by the selector name. elsif Nkind (Nam) = N_Selected_Component then Nam_Ent := Entity (Selector_Name (Nam)); if Ekind (Nam_Ent) /= E_Entry and then Ekind (Nam_Ent) /= E_Entry_Family and then Ekind (Nam_Ent) /= E_Function and then Ekind (Nam_Ent) /= E_Procedure then Error_Msg_N ("name in call is not a callable entity", Nam); Set_Etype (N, Any_Type); return; end if; -- If the name is an Indexed component, it can be a call to a member -- of an entry family. The prefix must be a selected component whose -- selector is the entry. Analyze_Procedure_Call normalizes several -- kinds of call into this form. elsif Nkind (Nam) = N_Indexed_Component then if Nkind (Prefix (Nam)) = N_Selected_Component then Nam_Ent := Entity (Selector_Name (Prefix (Nam))); else Error_Msg_N ("name in call is not a callable entity", Nam); Set_Etype (N, Any_Type); return; end if; elsif not Is_Entity_Name (Nam) then Error_Msg_N ("name in call is not a callable entity", Nam); Set_Etype (N, Any_Type); return; else Nam_Ent := Entity (Nam); -- If no interpretations, give error message if not Is_Overloadable (Nam_Ent) then No_Interpretation; return; end if; end if; -- Operations generated for RACW stub types are called only through -- dispatching, and can never be the static interpretation of a call. if Is_RACW_Stub_Type_Operation (Nam_Ent) then No_Interpretation; return; end if; Analyze_One_Call (N, Nam_Ent, True, Success); -- If this is an indirect call, the return type of the access_to -- subprogram may be an incomplete type. At the point of the call, -- use the full type if available, and at the same time update -- the return type of the access_to_subprogram. if Success and then Nkind (Nam) = N_Explicit_Dereference and then Ekind (Etype (N)) = E_Incomplete_Type and then Present (Full_View (Etype (N))) then Set_Etype (N, Full_View (Etype (N))); Set_Etype (Nam_Ent, Etype (N)); end if; else -- An overloaded selected component must denote overloaded operations -- of a concurrent type. The interpretations are attached to the -- simple name of those operations. if Nkind (Nam) = N_Selected_Component then Nam := Selector_Name (Nam); end if; Get_First_Interp (Nam, X, It); while Present (It.Nam) loop Nam_Ent := It.Nam; Deref := False; -- Name may be call that returns an access to subprogram, or more -- generally an overloaded expression one of whose interpretations -- yields an access to subprogram. If the name is an entity, we -- do not dereference, because the node is a call that returns -- the access type: note difference between f(x), where the call -- may return an access subprogram type, and f(x)(y), where the -- type returned by the call to f is implicitly dereferenced to -- analyze the outer call. if Is_Access_Type (Nam_Ent) then Nam_Ent := Designated_Type (Nam_Ent); elsif Is_Access_Type (Etype (Nam_Ent)) and then (not Is_Entity_Name (Nam) or else Nkind (N) = N_Procedure_Call_Statement) and then Ekind (Designated_Type (Etype (Nam_Ent))) = E_Subprogram_Type then Nam_Ent := Designated_Type (Etype (Nam_Ent)); if Is_Entity_Name (Nam) then Deref := True; end if; end if; Analyze_One_Call (N, Nam_Ent, False, Success); -- If the interpretation succeeds, mark the proper type of the -- prefix (any valid candidate will do). If not, remove the -- candidate interpretation. This only needs to be done for -- overloaded protected operations, for other entities disambi- -- guation is done directly in Resolve. if Success then if Deref and then Nkind (Parent (N)) /= N_Explicit_Dereference then Set_Entity (Nam, It.Nam); Insert_Explicit_Dereference (Nam); Set_Etype (Nam, Nam_Ent); else Set_Etype (Nam, It.Typ); end if; elsif Nkind_In (Name (N), N_Selected_Component, N_Function_Call) then Remove_Interp (X); end if; Get_Next_Interp (X, It); end loop; -- If the name is the result of a function call, it can only -- be a call to a function returning an access to subprogram. -- Insert explicit dereference. if Nkind (Nam) = N_Function_Call then Insert_Explicit_Dereference (Nam); end if; if Etype (N) = Any_Type then -- None of the interpretations is compatible with the actuals Diagnose_Call (N, Nam); -- Special checks for uninstantiated put routines if Nkind (N) = N_Procedure_Call_Statement and then Is_Entity_Name (Nam) and then Chars (Nam) = Name_Put and then List_Length (Actuals) = 1 then declare Arg : constant Node_Id := First (Actuals); Typ : Entity_Id; begin if Nkind (Arg) = N_Parameter_Association then Typ := Etype (Explicit_Actual_Parameter (Arg)); else Typ := Etype (Arg); end if; if Is_Signed_Integer_Type (Typ) then Error_Msg_N ("possible missing instantiation of " & "'Text_'I'O.'Integer_'I'O!", Nam); elsif Is_Modular_Integer_Type (Typ) then Error_Msg_N ("possible missing instantiation of " & "'Text_'I'O.'Modular_'I'O!", Nam); elsif Is_Floating_Point_Type (Typ) then Error_Msg_N ("possible missing instantiation of " & "'Text_'I'O.'Float_'I'O!", Nam); elsif Is_Ordinary_Fixed_Point_Type (Typ) then Error_Msg_N ("possible missing instantiation of " & "'Text_'I'O.'Fixed_'I'O!", Nam); elsif Is_Decimal_Fixed_Point_Type (Typ) then Error_Msg_N ("possible missing instantiation of " & "'Text_'I'O.'Decimal_'I'O!", Nam); elsif Is_Enumeration_Type (Typ) then Error_Msg_N ("possible missing instantiation of " & "'Text_'I'O.'Enumeration_'I'O!", Nam); end if; end; end if; elsif not Is_Overloaded (N) and then Is_Entity_Name (Nam) then -- Resolution yields a single interpretation. Verify that the -- reference has capitalization consistent with the declaration. Set_Entity_With_Style_Check (Nam, Entity (Nam)); Generate_Reference (Entity (Nam), Nam); Set_Etype (Nam, Etype (Entity (Nam))); else Remove_Abstract_Operations (N); end if; End_Interp_List; end if; end Analyze_Call; --------------------------- -- Analyze_Comparison_Op -- --------------------------- procedure Analyze_Comparison_Op (N : Node_Id) is L : constant Node_Id := Left_Opnd (N); R : constant Node_Id := Right_Opnd (N); Op_Id : Entity_Id := Entity (N); begin Set_Etype (N, Any_Type); Candidate_Type := Empty; Analyze_Expression (L); Analyze_Expression (R); if Present (Op_Id) then if Ekind (Op_Id) = E_Operator then Find_Comparison_Types (L, R, Op_Id, N); else Add_One_Interp (N, Op_Id, Etype (Op_Id)); end if; if Is_Overloaded (L) then Set_Etype (L, Intersect_Types (L, R)); end if; else Op_Id := Get_Name_Entity_Id (Chars (N)); while Present (Op_Id) loop if Ekind (Op_Id) = E_Operator then Find_Comparison_Types (L, R, Op_Id, N); else Analyze_User_Defined_Binary_Op (N, Op_Id); end if; Op_Id := Homonym (Op_Id); end loop; end if; Operator_Check (N); end Analyze_Comparison_Op; --------------------------- -- Analyze_Concatenation -- --------------------------- procedure Analyze_Concatenation (N : Node_Id) is -- We wish to avoid deep recursion, because concatenations are often -- deeply nested, as in A&B&...&Z. Therefore, we walk down the left -- operands nonrecursively until we find something that is not a -- concatenation (A in this case), or has already been analyzed. We -- analyze that, and then walk back up the tree following Parent -- pointers, calling Analyze_Concatenation_Rest to do the rest of the -- work at each level. The Parent pointers allow us to avoid recursion, -- and thus avoid running out of memory. NN : Node_Id := N; L : Node_Id; begin Candidate_Type := Empty; -- The following code is equivalent to: -- Set_Etype (N, Any_Type); -- Analyze_Expression (Left_Opnd (N)); -- Analyze_Concatenation_Rest (N); -- where the Analyze_Expression call recurses back here if the left -- operand is a concatenation. -- Walk down left operands loop Set_Etype (NN, Any_Type); L := Left_Opnd (NN); exit when Nkind (L) /= N_Op_Concat or else Analyzed (L); NN := L; end loop; -- Now (given the above example) NN is A&B and L is A -- First analyze L ... Analyze_Expression (L); -- ... then walk NN back up until we reach N (where we started), calling -- Analyze_Concatenation_Rest along the way. loop Analyze_Concatenation_Rest (NN); exit when NN = N; NN := Parent (NN); end loop; end Analyze_Concatenation; -------------------------------- -- Analyze_Concatenation_Rest -- -------------------------------- -- If the only one-dimensional array type in scope is String, -- this is the resulting type of the operation. Otherwise there -- will be a concatenation operation defined for each user-defined -- one-dimensional array. procedure Analyze_Concatenation_Rest (N : Node_Id) is L : constant Node_Id := Left_Opnd (N); R : constant Node_Id := Right_Opnd (N); Op_Id : Entity_Id := Entity (N); LT : Entity_Id; RT : Entity_Id; begin Analyze_Expression (R); -- If the entity is present, the node appears in an instance, and -- denotes a predefined concatenation operation. The resulting type is -- obtained from the arguments when possible. If the arguments are -- aggregates, the array type and the concatenation type must be -- visible. if Present (Op_Id) then if Ekind (Op_Id) = E_Operator then LT := Base_Type (Etype (L)); RT := Base_Type (Etype (R)); if Is_Array_Type (LT) and then (RT = LT or else RT = Base_Type (Component_Type (LT))) then Add_One_Interp (N, Op_Id, LT); elsif Is_Array_Type (RT) and then LT = Base_Type (Component_Type (RT)) then Add_One_Interp (N, Op_Id, RT); -- If one operand is a string type or a user-defined array type, -- and the other is a literal, result is of the specific type. elsif (Root_Type (LT) = Standard_String or else Scope (LT) /= Standard_Standard) and then Etype (R) = Any_String then Add_One_Interp (N, Op_Id, LT); elsif (Root_Type (RT) = Standard_String or else Scope (RT) /= Standard_Standard) and then Etype (L) = Any_String then Add_One_Interp (N, Op_Id, RT); elsif not Is_Generic_Type (Etype (Op_Id)) then Add_One_Interp (N, Op_Id, Etype (Op_Id)); else -- Type and its operations must be visible Set_Entity (N, Empty); Analyze_Concatenation (N); end if; else Add_One_Interp (N, Op_Id, Etype (Op_Id)); end if; else Op_Id := Get_Name_Entity_Id (Name_Op_Concat); while Present (Op_Id) loop if Ekind (Op_Id) = E_Operator then -- Do not consider operators declared in dead code, they can -- not be part of the resolution. if Is_Eliminated (Op_Id) then null; else Find_Concatenation_Types (L, R, Op_Id, N); end if; else Analyze_User_Defined_Binary_Op (N, Op_Id); end if; Op_Id := Homonym (Op_Id); end loop; end if; Operator_Check (N); end Analyze_Concatenation_Rest; ------------------------------------ -- Analyze_Conditional_Expression -- ------------------------------------ procedure Analyze_Conditional_Expression (N : Node_Id) is Condition : constant Node_Id := First (Expressions (N)); Then_Expr : constant Node_Id := Next (Condition); Else_Expr : constant Node_Id := Next (Then_Expr); begin if Comes_From_Source (N) then Check_Compiler_Unit (N); end if; Analyze_Expression (Condition); Analyze_Expression (Then_Expr); if Present (Else_Expr) then Analyze_Expression (Else_Expr); end if; if not Is_Overloaded (Then_Expr) then Set_Etype (N, Etype (Then_Expr)); else declare I : Interp_Index; It : Interp; begin Set_Etype (N, Any_Type); Get_First_Interp (Then_Expr, I, It); while Present (It.Nam) loop if Has_Compatible_Type (Else_Expr, It.Typ) then Add_One_Interp (N, It.Typ, It.Typ); end if; Get_Next_Interp (I, It); end loop; end; end if; end Analyze_Conditional_Expression; ------------------------- -- Analyze_Equality_Op -- ------------------------- procedure Analyze_Equality_Op (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); L : constant Node_Id := Left_Opnd (N); R : constant Node_Id := Right_Opnd (N); Op_Id : Entity_Id; begin Set_Etype (N, Any_Type); Candidate_Type := Empty; Analyze_Expression (L); Analyze_Expression (R); -- If the entity is set, the node is a generic instance with a non-local -- reference to the predefined operator or to a user-defined function. -- It can also be an inequality that is expanded into the negation of a -- call to a user-defined equality operator. -- For the predefined case, the result is Boolean, regardless of the -- type of the operands. The operands may even be limited, if they are -- generic actuals. If they are overloaded, label the left argument with -- the common type that must be present, or with the type of the formal -- of the user-defined function. if Present (Entity (N)) then Op_Id := Entity (N); if Ekind (Op_Id) = E_Operator then Add_One_Interp (N, Op_Id, Standard_Boolean); else Add_One_Interp (N, Op_Id, Etype (Op_Id)); end if; if Is_Overloaded (L) then if Ekind (Op_Id) = E_Operator then Set_Etype (L, Intersect_Types (L, R)); else Set_Etype (L, Etype (First_Formal (Op_Id))); end if; end if; else Op_Id := Get_Name_Entity_Id (Chars (N)); while Present (Op_Id) loop if Ekind (Op_Id) = E_Operator then Find_Equality_Types (L, R, Op_Id, N); else Analyze_User_Defined_Binary_Op (N, Op_Id); end if; Op_Id := Homonym (Op_Id); end loop; end if; -- If there was no match, and the operator is inequality, this may -- be a case where inequality has not been made explicit, as for -- tagged types. Analyze the node as the negation of an equality -- operation. This cannot be done earlier, because before analysis -- we cannot rule out the presence of an explicit inequality. if Etype (N) = Any_Type and then Nkind (N) = N_Op_Ne then Op_Id := Get_Name_Entity_Id (Name_Op_Eq); while Present (Op_Id) loop if Ekind (Op_Id) = E_Operator then Find_Equality_Types (L, R, Op_Id, N); else Analyze_User_Defined_Binary_Op (N, Op_Id); end if; Op_Id := Homonym (Op_Id); end loop; if Etype (N) /= Any_Type then Op_Id := Entity (N); Rewrite (N, Make_Op_Not (Loc, Right_Opnd => Make_Op_Eq (Loc, Left_Opnd => Left_Opnd (N), Right_Opnd => Right_Opnd (N)))); Set_Entity (Right_Opnd (N), Op_Id); Analyze (N); end if; end if; Operator_Check (N); end Analyze_Equality_Op; ---------------------------------- -- Analyze_Explicit_Dereference -- ---------------------------------- procedure Analyze_Explicit_Dereference (N : Node_Id) is Loc : constant Source_Ptr := Sloc (N); P : constant Node_Id := Prefix (N); T : Entity_Id; I : Interp_Index; It : Interp; New_N : Node_Id; function Is_Function_Type return Boolean; -- Check whether node may be interpreted as an implicit function call ---------------------- -- Is_Function_Type -- ---------------------- function Is_Function_Type return Boolean is I : Interp_Index; It : Interp; begin if not Is_Overloaded (N) then return Ekind (Base_Type (Etype (N))) = E_Subprogram_Type and then Etype (Base_Type (Etype (N))) /= Standard_Void_Type; else Get_First_Interp (N, I, It); while Present (It.Nam) loop if Ekind (Base_Type (It.Typ)) /= E_Subprogram_Type or else Etype (Base_Type (It.Typ)) = Standard_Void_Type then return False; end if; Get_Next_Interp (I, It); end loop; return True; end if; end Is_Function_Type; -- Start of processing for Analyze_Explicit_Dereference begin Analyze (P); Set_Etype (N, Any_Type); -- Test for remote access to subprogram type, and if so return -- after rewriting the original tree. if Remote_AST_E_Dereference (P) then return; end if; -- Normal processing for other than remote access to subprogram type if not Is_Overloaded (P) then if Is_Access_Type (Etype (P)) then -- Set the Etype. We need to go through Is_For_Access_Subtypes to -- avoid other problems caused by the Private_Subtype and it is -- safe to go to the Base_Type because this is the same as -- converting the access value to its Base_Type. declare DT : Entity_Id := Designated_Type (Etype (P)); begin if Ekind (DT) = E_Private_Subtype and then Is_For_Access_Subtype (DT) then DT := Base_Type (DT); end if; -- An explicit dereference is a legal occurrence of an -- incomplete type imported through a limited_with clause, -- if the full view is visible. if From_With_Type (DT) and then not From_With_Type (Scope (DT)) and then (Is_Immediately_Visible (Scope (DT)) or else (Is_Child_Unit (Scope (DT)) and then Is_Visible_Child_Unit (Scope (DT)))) then Set_Etype (N, Available_View (DT)); else Set_Etype (N, DT); end if; end; elsif Etype (P) /= Any_Type then Error_Msg_N ("prefix of dereference must be an access type", N); return; end if; else Get_First_Interp (P, I, It); while Present (It.Nam) loop T := It.Typ; if Is_Access_Type (T) then Add_One_Interp (N, Designated_Type (T), Designated_Type (T)); end if; Get_Next_Interp (I, It); end loop; -- Error if no interpretation of the prefix has an access type if Etype (N) = Any_Type then Error_Msg_N ("access type required in prefix of explicit dereference", P); Set_Etype (N, Any_Type); return; end if; end if; if Is_Function_Type and then Nkind (Parent (N)) /= N_Indexed_Component and then (Nkind (Parent (N)) /= N_Function_Call or else N /= Name (Parent (N))) and then (Nkind (Parent (N)) /= N_Procedure_Call_Statement or else N /= Name (Parent (N))) and then Nkind (Parent (N)) /= N_Subprogram_Renaming_Declaration and then (Nkind (Parent (N)) /= N_Attribute_Reference or else (Attribute_Name (Parent (N)) /= Name_Address and then Attribute_Name (Parent (N)) /= Name_Access)) then -- Name is a function call with no actuals, in a context that -- requires deproceduring (including as an actual in an enclosing -- function or procedure call). There are some pathological cases -- where the prefix might include functions that return access to -- subprograms and others that return a regular type. Disambiguation -- of those has to take place in Resolve. New_N := Make_Function_Call (Loc, Name => Make_Explicit_Dereference (Loc, P), Parameter_Associations => New_List); -- If the prefix is overloaded, remove operations that have formals, -- we know that this is a parameterless call. if Is_Overloaded (P) then Get_First_Interp (P, I, It); while Present (It.Nam) loop T := It.Typ; if No (First_Formal (Base_Type (Designated_Type (T)))) then Set_Etype (P, T); else Remove_Interp (I); end if; Get_Next_Interp (I, It); end loop; end if; Rewrite (N, New_N); Analyze (N); elsif not Is_Function_Type and then Is_Overloaded (N) then -- The prefix may include access to subprograms and other access -- types. If the context selects the interpretation that is a -- function call (not a procedure call) we cannot rewrite the node -- yet, but we include the result of the call interpretation. Get_First_Interp (N, I, It); while Present (It.Nam) loop if Ekind (Base_Type (It.Typ)) = E_Subprogram_Type and then Etype (Base_Type (It.Typ)) /= Standard_Void_Type and then Nkind (Parent (N)) /= N_Procedure_Call_Statement then Add_One_Interp (N, Etype (It.Typ), Etype (It.Typ)); end if; Get_Next_Interp (I, It); end loop; end if; -- A value of remote access-to-class-wide must not be dereferenced -- (RM E.2.2(16)). Validate_Remote_Access_To_Class_Wide_Type (N); end Analyze_Explicit_Dereference; ------------------------ -- Analyze_Expression -- ------------------------ procedure Analyze_Expression (N : Node_Id) is begin Analyze (N); Check_Parameterless_Call (N); end Analyze_Expression; ------------------------------------ -- Analyze_Indexed_Component_Form -- ------------------------------------ procedure Analyze_Indexed_Component_Form (N : Node_Id) is P : constant Node_Id := Prefix (N); Exprs : constant List_Id := Expressions (N); Exp : Node_Id; P_T : Entity_Id; E : Node_Id; U_N : Entity_Id; procedure Process_Function_Call; -- Prefix in indexed component form is an overloadable entity, -- so the node is a function call. Reformat it as such. procedure Process_Indexed_Component; -- Prefix in indexed component form is actually an indexed component. -- This routine processes it, knowing that the prefix is already -- resolved. procedure Process_Indexed_Component_Or_Slice; -- An indexed component with a single index may designate a slice if -- the index is a subtype mark. This routine disambiguates these two -- cases by resolving the prefix to see if it is a subtype mark. procedure Process_Overloaded_Indexed_Component; -- If the prefix of an indexed component is overloaded, the proper -- interpretation is selected by the index types and the context. --------------------------- -- Process_Function_Call -- --------------------------- procedure Process_Function_Call is Actual : Node_Id; begin Change_Node (N, N_Function_Call); Set_Name (N, P); Set_Parameter_Associations (N, Exprs); -- Analyze actuals prior to analyzing the call itself Actual := First (Parameter_Associations (N)); while Present (Actual) loop Analyze (Actual); Check_Parameterless_Call (Actual); -- Move to next actual. Note that we use Next, not Next_Actual -- here. The reason for this is a bit subtle. If a function call -- includes named associations, the parser recognizes the node as -- a call, and it is analyzed as such. If all associations are -- positional, the parser builds an indexed_component node, and -- it is only after analysis of the prefix that the construct -- is recognized as a call, in which case Process_Function_Call -- rewrites the node and analyzes the actuals. If the list of -- actuals is malformed, the parser may leave the node as an -- indexed component (despite the presence of named associations). -- The iterator Next_Actual is equivalent to Next if the list is -- positional, but follows the normalized chain of actuals when -- named associations are present. In this case normalization has -- not taken place, and actuals remain unanalyzed, which leads to -- subsequent crashes or loops if there is an attempt to continue -- analysis of the program. Next (Actual); end loop; Analyze_Call (N); end Process_Function_Call; ------------------------------- -- Process_Indexed_Component -- ------------------------------- procedure Process_Indexed_Component is Exp : Node_Id; Array_Type : Entity_Id; Index : Node_Id; Pent : Entity_Id := Empty; begin Exp := First (Exprs); if Is_Overloaded (P) then Process_Overloaded_Indexed_Component; else Array_Type := Etype (P); if Is_Entity_Name (P) then Pent := Entity (P); elsif Nkind (P) = N_Selected_Component and then Is_Entity_Name (Selector_Name (P)) then Pent := Entity (Selector_Name (P)); end if; -- Prefix must be appropriate for an array type, taking into -- account a possible implicit dereference. if Is_Access_Type (Array_Type) then Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); Array_Type := Process_Implicit_Dereference_Prefix (Pent, P); end if; if Is_Array_Type (Array_Type) then null; elsif Present (Pent) and then Ekind (Pent) = E_Entry_Family then Analyze (Exp); Set_Etype (N, Any_Type); if not Has_Compatible_Type (Exp, Entry_Index_Type (Pent)) then Error_Msg_N ("invalid index type in entry name", N); elsif Present (Next (Exp)) then Error_Msg_N ("too many subscripts in entry reference", N); else Set_Etype (N, Etype (P)); end if; return; elsif Is_Record_Type (Array_Type) and then Remote_AST_I_Dereference (P) then return; elsif Array_Type = Any_Type then Set_Etype (N, Any_Type); -- In most cases the analysis of the prefix will have emitted -- an error already, but if the prefix may be interpreted as a -- call in prefixed notation, the report is left to the caller. -- To prevent cascaded errors, report only if no previous ones. if Serious_Errors_Detected = 0 then Error_Msg_N ("invalid prefix in indexed component", P); if Nkind (P) = N_Expanded_Name then Error_Msg_NE ("\& is not visible", P, Selector_Name (P)); end if; end if; return; -- Here we definitely have a bad indexing else if Nkind (Parent (N)) = N_Requeue_Statement and then Present (Pent) and then Ekind (Pent) = E_Entry then Error_Msg_N ("REQUEUE does not permit parameters", First (Exprs)); elsif Is_Entity_Name (P) and then Etype (P) = Standard_Void_Type then Error_Msg_NE ("incorrect use of&", P, Entity (P)); else Error_Msg_N ("array type required in indexed component", P); end if; Set_Etype (N, Any_Type); return; end if; Index := First_Index (Array_Type); while Present (Index) and then Present (Exp) loop if not Has_Compatible_Type (Exp, Etype (Index)) then Wrong_Type (Exp, Etype (Index)); Set_Etype (N, Any_Type); return; end if; Next_Index (Index); Next (Exp); end loop; Set_Etype (N, Component_Type (Array_Type)); if Present (Index) then Error_Msg_N ("too few subscripts in array reference", First (Exprs)); elsif Present (Exp) then Error_Msg_N ("too many subscripts in array reference", Exp); end if; end if; end Process_Indexed_Component; ---------------------------------------- -- Process_Indexed_Component_Or_Slice -- ---------------------------------------- procedure Process_Indexed_Component_Or_Slice is begin Exp := First (Exprs); while Present (Exp) loop Analyze_Expression (Exp); Next (Exp); end loop; Exp := First (Exprs); -- If one index is present, and it is a subtype name, then the -- node denotes a slice (note that the case of an explicit range -- for a slice was already built as an N_Slice node in the first -- place, so that case is not handled here). -- We use a replace rather than a rewrite here because this is one -- of the cases in which the tree built by the parser is plain wrong. if No (Next (Exp)) and then Is_Entity_Name (Exp) and then Is_Type (Entity (Exp)) then Replace (N, Make_Slice (Sloc (N), Prefix => P, Discrete_Range => New_Copy (Exp))); Analyze (N); -- Otherwise (more than one index present, or single index is not -- a subtype name), then we have the indexed component case. else Process_Indexed_Component; end if; end Process_Indexed_Component_Or_Slice; ------------------------------------------ -- Process_Overloaded_Indexed_Component -- ------------------------------------------ procedure Process_Overloaded_Indexed_Component is Exp : Node_Id; I : Interp_Index; It : Interp; Typ : Entity_Id; Index : Node_Id; Found : Boolean; begin Set_Etype (N, Any_Type); Get_First_Interp (P, I, It); while Present (It.Nam) loop Typ := It.Typ; if Is_Access_Type (Typ) then Typ := Designated_Type (Typ); Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); end if; if Is_Array_Type (Typ) then -- Got a candidate: verify that index types are compatible Index := First_Index (Typ); Found := True; Exp := First (Exprs); while Present (Index) and then Present (Exp) loop if Has_Compatible_Type (Exp, Etype (Index)) then null; else Found := False; Remove_Interp (I); exit; end if; Next_Index (Index); Next (Exp); end loop; if Found and then No (Index) and then No (Exp) then Add_One_Interp (N, Etype (Component_Type (Typ)), Etype (Component_Type (Typ))); end if; end if; Get_Next_Interp (I, It); end loop; if Etype (N) = Any_Type then Error_Msg_N ("no legal interpretation for indexed component", N); Set_Is_Overloaded (N, False); end if; End_Interp_List; end Process_Overloaded_Indexed_Component; -- Start of processing for Analyze_Indexed_Component_Form begin -- Get name of array, function or type Analyze (P); if Nkind_In (N, N_Function_Call, N_Procedure_Call_Statement) then -- If P is an explicit dereference whose prefix is of a -- remote access-to-subprogram type, then N has already -- been rewritten as a subprogram call and analyzed. return; end if; pragma Assert (Nkind (N) = N_Indexed_Component); P_T := Base_Type (Etype (P)); if Is_Entity_Name (P) or else Nkind (P) = N_Operator_Symbol then U_N := Entity (P); if Is_Type (U_N) then -- Reformat node as a type conversion E := Remove_Head (Exprs); if Present (First (Exprs)) then Error_Msg_N ("argument of type conversion must be single expression", N); end if; Change_Node (N, N_Type_Conversion); Set_Subtype_Mark (N, P); Set_Etype (N, U_N); Set_Expression (N, E); -- After changing the node, call for the specific Analysis -- routine directly, to avoid a double call to the expander. Analyze_Type_Conversion (N); return; end if; if Is_Overloadable (U_N) then Process_Function_Call; elsif Ekind (Etype (P)) = E_Subprogram_Type or else (Is_Access_Type (Etype (P)) and then Ekind (Designated_Type (Etype (P))) = E_Subprogram_Type) then -- Call to access_to-subprogram with possible implicit dereference Process_Function_Call; elsif Is_Generic_Subprogram (U_N) then -- A common beginner's (or C++ templates fan) error Error_Msg_N ("generic subprogram cannot be called", N); Set_Etype (N, Any_Type); return; else Process_Indexed_Component_Or_Slice; end if; -- If not an entity name, prefix is an expression that may denote -- an array or an access-to-subprogram. else if Ekind (P_T) = E_Subprogram_Type or else (Is_Access_Type (P_T) and then Ekind (Designated_Type (P_T)) = E_Subprogram_Type) then Process_Function_Call; elsif Nkind (P) = N_Selected_Component and then Is_Overloadable (Entity (Selector_Name (P))) then Process_Function_Call; else -- Indexed component, slice, or a call to a member of a family -- entry, which will be converted to an entry call later. Process_Indexed_Component_Or_Slice; end if; end if; end Analyze_Indexed_Component_Form; ------------------------ -- Analyze_Logical_Op -- ------------------------ procedure Analyze_Logical_Op (N : Node_Id) is L : constant Node_Id := Left_Opnd (N); R : constant Node_Id := Right_Opnd (N); Op_Id : Entity_Id := Entity (N); begin Set_Etype (N, Any_Type); Candidate_Type := Empty; Analyze_Expression (L); Analyze_Expression (R); if Present (Op_Id) then if Ekind (Op_Id) = E_Operator then Find_Boolean_Types (L, R, Op_Id, N); else Add_One_Interp (N, Op_Id, Etype (Op_Id)); end if; else Op_Id := Get_Name_Entity_Id (Chars (N)); while Present (Op_Id) loop if Ekind (Op_Id) = E_Operator then Find_Boolean_Types (L, R, Op_Id, N); else Analyze_User_Defined_Binary_Op (N, Op_Id); end if; Op_Id := Homonym (Op_Id); end loop; end if; Operator_Check (N); end Analyze_Logical_Op; --------------------------- -- Analyze_Membership_Op -- --------------------------- procedure Analyze_Membership_Op (N : Node_Id) is L : constant Node_Id := Left_Opnd (N); R : constant Node_Id := Right_Opnd (N); Index : Interp_Index; It : Interp; Found : Boolean := False; I_F : Interp_Index; T_F : Entity_Id; procedure Try_One_Interp (T1 : Entity_Id); -- Routine to try one proposed interpretation. Note that the context -- of the operation plays no role in resolving the arguments, so that -- if there is more than one interpretation of the operands that is -- compatible with a membership test, the operation is ambiguous. -------------------- -- Try_One_Interp -- -------------------- procedure Try_One_Interp (T1 : Entity_Id) is begin if Has_Compatible_Type (R, T1) then if Found and then Base_Type (T1) /= Base_Type (T_F) then It := Disambiguate (L, I_F, Index, Any_Type); if It = No_Interp then Ambiguous_Operands (N); Set_Etype (L, Any_Type); return; else T_F := It.Typ; end if; else Found := True; T_F := T1; I_F := Index; end if; Set_Etype (L, T_F); end if; end Try_One_Interp; procedure Analyze_Set_Membership; -- If a set of alternatives is present, analyze each and find the -- common type to which they must all resolve. ---------------------------- -- Analyze_Set_Membership -- ---------------------------- procedure Analyze_Set_Membership is Alt : Node_Id; Index : Interp_Index; It : Interp; Candidate_Interps : Node_Id; Common_Type : Entity_Id := Empty; begin Analyze (L); Candidate_Interps := L; if not Is_Overloaded (L) then Common_Type := Etype (L); Alt := First (Alternatives (N)); while Present (Alt) loop Analyze (Alt); if not Has_Compatible_Type (Alt, Common_Type) then Wrong_Type (Alt, Common_Type); end if; Next (Alt); end loop; else Alt := First (Alternatives (N)); while Present (Alt) loop Analyze (Alt); if not Is_Overloaded (Alt) then Common_Type := Etype (Alt); else Get_First_Interp (Alt, Index, It); while Present (It.Typ) loop if not Has_Compatible_Type (Candidate_Interps, It.Typ) then Remove_Interp (Index); end if; Get_Next_Interp (Index, It); end loop; Get_First_Interp (Alt, Index, It); if No (It.Typ) then Error_Msg_N ("alternative has no legal type", Alt); return; end if; -- If alternative is not overloaded, we have a unique type -- for all of them. Set_Etype (Alt, It.Typ); Get_Next_Interp (Index, It); if No (It.Typ) then Set_Is_Overloaded (Alt, False); Common_Type := Etype (Alt); end if; Candidate_Interps := Alt; end if; Next (Alt); end loop; end if; Set_Etype (N, Standard_Boolean); if Present (Common_Type) then Set_Etype (L, Common_Type); Set_Is_Overloaded (L, False); else Error_Msg_N ("cannot resolve membership operation", N); end if; end Analyze_Set_Membership; -- Start of processing for Analyze_Membership_Op begin Analyze_Expression (L); if No (R) and then Extensions_Allowed then Analyze_Set_Membership; return; end if; if Nkind (R) = N_Range or else (Nkind (R) = N_Attribute_Reference and then Attribute_Name (R) = Name_Range) then Analyze (R); if not Is_Overloaded (L) then Try_One_Interp (Etype (L)); else Get_First_Interp (L, Index, It); while Present (It.Typ) loop Try_One_Interp (It.Typ); Get_Next_Interp (Index, It); end loop; end if; -- If not a range, it can only be a subtype mark, or else there -- is a more basic error, to be diagnosed in Find_Type. else Find_Type (R); if Is_Entity_Name (R) then Check_Fully_Declared (Entity (R), R); end if; end if; -- Compatibility between expression and subtype mark or range is -- checked during resolution. The result of the operation is Boolean -- in any case. Set_Etype (N, Standard_Boolean); if Comes_From_Source (N) and then Present (Right_Opnd (N)) and then Is_CPP_Class (Etype (Etype (Right_Opnd (N)))) then Error_Msg_N ("membership test not applicable to cpp-class types", N); end if; end Analyze_Membership_Op; ---------------------- -- Analyze_Negation -- ---------------------- procedure Analyze_Negation (N : Node_Id) is R : constant Node_Id := Right_Opnd (N); Op_Id : Entity_Id := Entity (N); begin Set_Etype (N, Any_Type); Candidate_Type := Empty; Analyze_Expression (R); if Present (Op_Id) then if Ekind (Op_Id) = E_Operator then Find_Negation_Types (R, Op_Id, N); else Add_One_Interp (N, Op_Id, Etype (Op_Id)); end if; else Op_Id := Get_Name_Entity_Id (Chars (N)); while Present (Op_Id) loop if Ekind (Op_Id) = E_Operator then Find_Negation_Types (R, Op_Id, N); else Analyze_User_Defined_Unary_Op (N, Op_Id); end if; Op_Id := Homonym (Op_Id); end loop; end if; Operator_Check (N); end Analyze_Negation; ------------------ -- Analyze_Null -- ------------------ procedure Analyze_Null (N : Node_Id) is begin Set_Etype (N, Any_Access); end Analyze_Null; ---------------------- -- Analyze_One_Call -- ---------------------- procedure Analyze_One_Call (N : Node_Id; Nam : Entity_Id; Report : Boolean; Success : out Boolean; Skip_First : Boolean := False) is Actuals : constant List_Id := Parameter_Associations (N); Prev_T : constant Entity_Id := Etype (N); Must_Skip : constant Boolean := Skip_First or else Nkind (Original_Node (N)) = N_Selected_Component or else (Nkind (Original_Node (N)) = N_Indexed_Component and then Nkind (Prefix (Original_Node (N))) = N_Selected_Component); -- The first formal must be omitted from the match when trying to find -- a primitive operation that is a possible interpretation, and also -- after the call has been rewritten, because the corresponding actual -- is already known to be compatible, and because this may be an -- indexing of a call with default parameters. Formal : Entity_Id; Actual : Node_Id; Is_Indexed : Boolean := False; Is_Indirect : Boolean := False; Subp_Type : constant Entity_Id := Etype (Nam); Norm_OK : Boolean; function Operator_Hidden_By (Fun : Entity_Id) return Boolean; -- There may be a user-defined operator that hides the current -- interpretation. We must check for this independently of the -- analysis of the call with the user-defined operation, because -- the parameter names may be wrong and yet the hiding takes place. -- This fixes a problem with ACATS test B34014O. -- -- When the type Address is a visible integer type, and the DEC -- system extension is visible, the predefined operator may be -- hidden as well, by one of the address operations in auxdec. -- Finally, The abstract operations on address do not hide the -- predefined operator (this is the purpose of making them abstract). procedure Indicate_Name_And_Type; -- If candidate interpretation matches, indicate name and type of -- result on call node. ---------------------------- -- Indicate_Name_And_Type -- ---------------------------- procedure Indicate_Name_And_Type is begin Add_One_Interp (N, Nam, Etype (Nam)); Success := True; -- If the prefix of the call is a name, indicate the entity -- being called. If it is not a name, it is an expression that -- denotes an access to subprogram or else an entry or family. In -- the latter case, the name is a selected component, and the entity -- being called is noted on the selector. if not Is_Type (Nam) then if Is_Entity_Name (Name (N)) or else Nkind (Name (N)) = N_Operator_Symbol then Set_Entity (Name (N), Nam); elsif Nkind (Name (N)) = N_Selected_Component then Set_Entity (Selector_Name (Name (N)), Nam); end if; end if; if Debug_Flag_E and not Report then Write_Str (" Overloaded call "); Write_Int (Int (N)); Write_Str (" compatible with "); Write_Int (Int (Nam)); Write_Eol; end if; end Indicate_Name_And_Type; ------------------------ -- Operator_Hidden_By -- ------------------------ function Operator_Hidden_By (Fun : Entity_Id) return Boolean is Act1 : constant Node_Id := First_Actual (N); Act2 : constant Node_Id := Next_Actual (Act1); Form1 : constant Entity_Id := First_Formal (Fun); Form2 : constant Entity_Id := Next_Formal (Form1); begin if Ekind (Fun) /= E_Function or else Is_Abstract_Subprogram (Fun) then return False; elsif not Has_Compatible_Type (Act1, Etype (Form1)) then return False; elsif Present (Form2) then if No (Act2) or else not Has_Compatible_Type (Act2, Etype (Form2)) then return False; end if; elsif Present (Act2) then return False; end if; -- Now we know that the arity of the operator matches the function, -- and the function call is a valid interpretation. The function -- hides the operator if it has the right signature, or if one of -- its operands is a non-abstract operation on Address when this is -- a visible integer type. return Hides_Op (Fun, Nam) or else Is_Descendent_Of_Address (Etype (Form1)) or else (Present (Form2) and then Is_Descendent_Of_Address (Etype (Form2))); end Operator_Hidden_By; -- Start of processing for Analyze_One_Call begin Success := False; -- If the subprogram has no formals or if all the formals have defaults, -- and the return type is an array type, the node may denote an indexing -- of the result of a parameterless call. In Ada 2005, the subprogram -- may have one non-defaulted formal, and the call may have been written -- in prefix notation, so that the rebuilt parameter list has more than -- one actual. if not Is_Overloadable (Nam) and then Ekind (Nam) /= E_Subprogram_Type and then Ekind (Nam) /= E_Entry_Family then return; end if; -- An indexing requires at least one actual if not Is_Empty_List (Actuals) and then (Needs_No_Actuals (Nam) or else (Needs_One_Actual (Nam) and then Present (Next_Actual (First (Actuals))))) then if Is_Array_Type (Subp_Type) then Is_Indexed := Try_Indexed_Call (N, Nam, Subp_Type, Must_Skip); elsif Is_Access_Type (Subp_Type) and then Is_Array_Type (Designated_Type (Subp_Type)) then Is_Indexed := Try_Indexed_Call (N, Nam, Designated_Type (Subp_Type), Must_Skip); -- The prefix can also be a parameterless function that returns an -- access to subprogram, in which case this is an indirect call. -- If this succeeds, an explicit dereference is added later on, -- in Analyze_Call or Resolve_Call. elsif Is_Access_Type (Subp_Type) and then Ekind (Designated_Type (Subp_Type)) = E_Subprogram_Type then Is_Indirect := Try_Indirect_Call (N, Nam, Subp_Type); end if; end if; -- If the call has been transformed into a slice, it is of the form -- F (Subtype) where F is parameterless. The node has been rewritten in -- Try_Indexed_Call and there is nothing else to do. if Is_Indexed and then Nkind (N) = N_Slice then return; end if; Normalize_Actuals (N, Nam, (Report and not Is_Indexed and not Is_Indirect), Norm_OK); if not Norm_OK then -- If an indirect call is a possible interpretation, indicate -- success to the caller. if Is_Indirect then Success := True; return; -- Mismatch in number or names of parameters elsif Debug_Flag_E then Write_Str (" normalization fails in call "); Write_Int (Int (N)); Write_Str (" with subprogram "); Write_Int (Int (Nam)); Write_Eol; end if; -- If the context expects a function call, discard any interpretation -- that is a procedure. If the node is not overloaded, leave as is for -- better error reporting when type mismatch is found. elsif Nkind (N) = N_Function_Call and then Is_Overloaded (Name (N)) and then Ekind (Nam) = E_Procedure then return; -- Ditto for function calls in a procedure context elsif Nkind (N) = N_Procedure_Call_Statement and then Is_Overloaded (Name (N)) and then Etype (Nam) /= Standard_Void_Type then return; elsif No (Actuals) then -- If Normalize succeeds, then there are default parameters for -- all formals. Indicate_Name_And_Type; elsif Ekind (Nam) = E_Operator then if Nkind (N) = N_Procedure_Call_Statement then return; end if; -- This can occur when the prefix of the call is an operator -- name or an expanded name whose selector is an operator name. Analyze_Operator_Call (N, Nam); if Etype (N) /= Prev_T then -- Check that operator is not hidden by a function interpretation if Is_Overloaded (Name (N)) then declare I : Interp_Index; It : Interp; begin Get_First_Interp (Name (N), I, It); while Present (It.Nam) loop if Operator_Hidden_By (It.Nam) then Set_Etype (N, Prev_T); return; end if; Get_Next_Interp (I, It); end loop; end; end if; -- If operator matches formals, record its name on the call. -- If the operator is overloaded, Resolve will select the -- correct one from the list of interpretations. The call -- node itself carries the first candidate. Set_Entity (Name (N), Nam); Success := True; elsif Report and then Etype (N) = Any_Type then Error_Msg_N ("incompatible arguments for operator", N); end if; else -- Normalize_Actuals has chained the named associations in the -- correct order of the formals. Actual := First_Actual (N); Formal := First_Formal (Nam); -- If we are analyzing a call rewritten from object notation, -- skip first actual, which may be rewritten later as an -- explicit dereference. if Must_Skip then Next_Actual (Actual); Next_Formal (Formal); end if; while Present (Actual) and then Present (Formal) loop if Nkind (Parent (Actual)) /= N_Parameter_Association or else Chars (Selector_Name (Parent (Actual))) = Chars (Formal) then -- The actual can be compatible with the formal, but we must -- also check that the context is not an address type that is -- visibly an integer type, as is the case in VMS_64. In this -- case the use of literals is illegal, except in the body of -- descendents of system, where arithmetic operations on -- address are of course used. if Has_Compatible_Type (Actual, Etype (Formal)) and then (Etype (Actual) /= Universal_Integer or else not Is_Descendent_Of_Address (Etype (Formal)) or else Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (N)))) then Next_Actual (Actual); Next_Formal (Formal); else if Debug_Flag_E then Write_Str (" type checking fails in call "); Write_Int (Int (N)); Write_Str (" with formal "); Write_Int (Int (Formal)); Write_Str (" in subprogram "); Write_Int (Int (Nam)); Write_Eol; end if; if Report and not Is_Indexed and not Is_Indirect then -- Ada 2005 (AI-251): Complete the error notification -- to help new Ada 2005 users. if Is_Class_Wide_Type (Etype (Formal)) and then Is_Interface (Etype (Etype (Formal))) and then not Interface_Present_In_Ancestor (Typ => Etype (Actual), Iface => Etype (Etype (Formal))) then Error_Msg_NE ("(Ada 2005) does not implement interface }", Actual, Etype (Etype (Formal))); end if; Wrong_Type (Actual, Etype (Formal)); if Nkind (Actual) = N_Op_Eq and then Nkind (Left_Opnd (Actual)) = N_Identifier then Formal := First_Formal (Nam); while Present (Formal) loop if Chars (Left_Opnd (Actual)) = Chars (Formal) then Error_Msg_N -- CODEFIX ("possible misspelling of `='>`!", Actual); exit; end if; Next_Formal (Formal); end loop; end if; if All_Errors_Mode then Error_Msg_Sloc := Sloc (Nam); if Is_Overloadable (Nam) and then Present (Alias (Nam)) and then not Comes_From_Source (Nam) then Error_Msg_NE ("\\ =='> in call to inherited operation & #!", Actual, Nam); elsif Ekind (Nam) = E_Subprogram_Type then declare Access_To_Subprogram_Typ : constant Entity_Id := Defining_Identifier (Associated_Node_For_Itype (Nam)); begin Error_Msg_NE ( "\\ =='> in call to dereference of &#!", Actual, Access_To_Subprogram_Typ); end; else Error_Msg_NE ("\\ =='> in call to &#!", Actual, Nam); end if; end if; end if; return; end if; else -- Normalize_Actuals has verified that a default value exists -- for this formal. Current actual names a subsequent formal. Next_Formal (Formal); end if; end loop; -- On exit, all actuals match Indicate_Name_And_Type; end if; end Analyze_One_Call; --------------------------- -- Analyze_Operator_Call -- --------------------------- procedure Analyze_Operator_Call (N : Node_Id; Op_Id : Entity_Id) is Op_Name : constant Name_Id := Chars (Op_Id); Act1 : constant Node_Id := First_Actual (N); Act2 : constant Node_Id := Next_Actual (Act1); begin -- Binary operator case if Present (Act2) then -- If more than two operands, then not binary operator after all if Present (Next_Actual (Act2)) then return; elsif Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract or else Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide or else Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem or else Op_Name = Name_Op_Expon then Find_Arithmetic_Types (Act1, Act2, Op_Id, N); elsif Op_Name = Name_Op_And or else Op_Name = Name_Op_Or or else Op_Name = Name_Op_Xor then Find_Boolean_Types (Act1, Act2, Op_Id, N); elsif Op_Name = Name_Op_Lt or else Op_Name = Name_Op_Le or else Op_Name = Name_Op_Gt or else Op_Name = Name_Op_Ge then Find_Comparison_Types (Act1, Act2, Op_Id, N); elsif Op_Name = Name_Op_Eq or else Op_Name = Name_Op_Ne then Find_Equality_Types (Act1, Act2, Op_Id, N); elsif Op_Name = Name_Op_Concat then Find_Concatenation_Types (Act1, Act2, Op_Id, N); -- Is this else null correct, or should it be an abort??? else null; end if; -- Unary operator case else if Op_Name = Name_Op_Subtract or else Op_Name = Name_Op_Add or else Op_Name = Name_Op_Abs then Find_Unary_Types (Act1, Op_Id, N); elsif Op_Name = Name_Op_Not then Find_Negation_Types (Act1, Op_Id, N); -- Is this else null correct, or should it be an abort??? else null; end if; end if; end Analyze_Operator_Call; ------------------------------------------- -- Analyze_Overloaded_Selected_Component -- ------------------------------------------- procedure Analyze_Overloaded_Selected_Component (N : Node_Id) is Nam : constant Node_Id := Prefix (N); Sel : constant Node_Id := Selector_Name (N); Comp : Entity_Id; I : Interp_Index; It : Interp; T : Entity_Id; begin Set_Etype (Sel, Any_Type); Get_First_Interp (Nam, I, It); while Present (It.Typ) loop if Is_Access_Type (It.Typ) then T := Designated_Type (It.Typ); Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); else T := It.Typ; end if; if Is_Record_Type (T) then -- If the prefix is a class-wide type, the visible components are -- those of the base type. if Is_Class_Wide_Type (T) then T := Etype (T); end if; Comp := First_Entity (T); while Present (Comp) loop if Chars (Comp) = Chars (Sel) and then Is_Visible_Component (Comp) then -- AI05-105: if the context is an object renaming with -- an anonymous access type, the expected type of the -- object must be anonymous. This is a name resolution rule. if Nkind (Parent (N)) /= N_Object_Renaming_Declaration or else No (Access_Definition (Parent (N))) or else Ekind (Etype (Comp)) = E_Anonymous_Access_Type or else Ekind (Etype (Comp)) = E_Anonymous_Access_Subprogram_Type then Set_Entity (Sel, Comp); Set_Etype (Sel, Etype (Comp)); Add_One_Interp (N, Etype (Comp), Etype (Comp)); -- This also specifies a candidate to resolve the name. -- Further overloading will be resolved from context. -- The selector name itself does not carry overloading -- information. Set_Etype (Nam, It.Typ); else -- Named access type in the context of a renaming -- declaration with an access definition. Remove -- inapplicable candidate. Remove_Interp (I); end if; end if; Next_Entity (Comp); end loop; elsif Is_Concurrent_Type (T) then Comp := First_Entity (T); while Present (Comp) and then Comp /= First_Private_Entity (T) loop if Chars (Comp) = Chars (Sel) then if Is_Overloadable (Comp) then Add_One_Interp (Sel, Comp, Etype (Comp)); else Set_Entity_With_Style_Check (Sel, Comp); Generate_Reference (Comp, Sel); end if; Set_Etype (Sel, Etype (Comp)); Set_Etype (N, Etype (Comp)); Set_Etype (Nam, It.Typ); -- For access type case, introduce explicit dereference for -- more uniform treatment of entry calls. Do this only once -- if several interpretations yield an access type. if Is_Access_Type (Etype (Nam)) and then Nkind (Nam) /= N_Explicit_Dereference then Insert_Explicit_Dereference (Nam); Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); end if; end if; Next_Entity (Comp); end loop; Set_Is_Overloaded (N, Is_Overloaded (Sel)); end if; Get_Next_Interp (I, It); end loop; if Etype (N) = Any_Type and then not Try_Object_Operation (N) then Error_Msg_NE ("undefined selector& for overloaded prefix", N, Sel); Set_Entity (Sel, Any_Id); Set_Etype (Sel, Any_Type); end if; end Analyze_Overloaded_Selected_Component; ---------------------------------- -- Analyze_Qualified_Expression -- ---------------------------------- procedure Analyze_Qualified_Expression (N : Node_Id) is Mark : constant Entity_Id := Subtype_Mark (N); Expr : constant Node_Id := Expression (N); I : Interp_Index; It : Interp; T : Entity_Id; begin Analyze_Expression (Expr); Set_Etype (N, Any_Type); Find_Type (Mark); T := Entity (Mark); Set_Etype (N, T); if T = Any_Type then return; end if; Check_Fully_Declared (T, N); -- If expected type is class-wide, check for exact match before -- expansion, because if the expression is a dispatching call it -- may be rewritten as explicit dereference with class-wide result. -- If expression is overloaded, retain only interpretations that -- will yield exact matches. if Is_Class_Wide_Type (T) then if not Is_Overloaded (Expr) then if Base_Type (Etype (Expr)) /= Base_Type (T) then if Nkind (Expr) = N_Aggregate then Error_Msg_N ("type of aggregate cannot be class-wide", Expr); else Wrong_Type (Expr, T); end if; end if; else Get_First_Interp (Expr, I, It); while Present (It.Nam) loop if Base_Type (It.Typ) /= Base_Type (T) then Remove_Interp (I); end if; Get_Next_Interp (I, It); end loop; end if; end if; Set_Etype (N, T); end Analyze_Qualified_Expression; ------------------- -- Analyze_Range -- ------------------- procedure Analyze_Range (N : Node_Id) is L : constant Node_Id := Low_Bound (N); H : constant Node_Id := High_Bound (N); I1, I2 : Interp_Index; It1, It2 : Interp; procedure Check_Common_Type (T1, T2 : Entity_Id); -- Verify the compatibility of two types, and choose the -- non universal one if the other is universal. procedure Check_High_Bound (T : Entity_Id); -- Test one interpretation of the low bound against all those -- of the high bound. procedure Check_Universal_Expression (N : Node_Id); -- In Ada83, reject bounds of a universal range that are not -- literals or entity names. ----------------------- -- Check_Common_Type -- ----------------------- procedure Check_Common_Type (T1, T2 : Entity_Id) is begin if Covers (T1 => T1, T2 => T2) or else Covers (T1 => T2, T2 => T1) then if T1 = Universal_Integer or else T1 = Universal_Real or else T1 = Any_Character then Add_One_Interp (N, Base_Type (T2), Base_Type (T2)); elsif T1 = T2 then Add_One_Interp (N, T1, T1); else Add_One_Interp (N, Base_Type (T1), Base_Type (T1)); end if; end if; end Check_Common_Type; ---------------------- -- Check_High_Bound -- ---------------------- procedure Check_High_Bound (T : Entity_Id) is begin if not Is_Overloaded (H) then Check_Common_Type (T, Etype (H)); else Get_First_Interp (H, I2, It2); while Present (It2.Typ) loop Check_Common_Type (T, It2.Typ); Get_Next_Interp (I2, It2); end loop; end if; end Check_High_Bound; ----------------------------- -- Is_Universal_Expression -- ----------------------------- procedure Check_Universal_Expression (N : Node_Id) is begin if Etype (N) = Universal_Integer and then Nkind (N) /= N_Integer_Literal and then not Is_Entity_Name (N) and then Nkind (N) /= N_Attribute_Reference then Error_Msg_N ("illegal bound in discrete range", N); end if; end Check_Universal_Expression; -- Start of processing for Analyze_Range begin Set_Etype (N, Any_Type); Analyze_Expression (L); Analyze_Expression (H); if Etype (L) = Any_Type or else Etype (H) = Any_Type then return; else if not Is_Overloaded (L) then Check_High_Bound (Etype (L)); else Get_First_Interp (L, I1, It1); while Present (It1.Typ) loop Check_High_Bound (It1.Typ); Get_Next_Interp (I1, It1); end loop; end if; -- If result is Any_Type, then we did not find a compatible pair if Etype (N) = Any_Type then Error_Msg_N ("incompatible types in range ", N); end if; end if; if Ada_Version = Ada_83 and then (Nkind (Parent (N)) = N_Loop_Parameter_Specification or else Nkind (Parent (N)) = N_Constrained_Array_Definition) then Check_Universal_Expression (L); Check_Universal_Expression (H); end if; end Analyze_Range; ----------------------- -- Analyze_Reference -- ----------------------- procedure Analyze_Reference (N : Node_Id) is P : constant Node_Id := Prefix (N); E : Entity_Id; T : Entity_Id; Acc_Type : Entity_Id; begin Analyze (P); -- An interesting error check, if we take the 'Reference of an object -- for which a pragma Atomic or Volatile has been given, and the type -- of the object is not Atomic or Volatile, then we are in trouble. The -- problem is that no trace of the atomic/volatile status will remain -- for the backend to respect when it deals with the resulting pointer, -- since the pointer type will not be marked atomic (it is a pointer to -- the base type of the object). -- It is not clear if that can ever occur, but in case it does, we will -- generate an error message. Not clear if this message can ever be -- generated, and pretty clear that it represents a bug if it is, still -- seems worth checking! T := Etype (P); if Is_Entity_Name (P) and then Is_Object_Reference (P) then E := Entity (P); T := Etype (P); if (Has_Atomic_Components (E) and then not Has_Atomic_Components (T)) or else (Has_Volatile_Components (E) and then not Has_Volatile_Components (T)) or else (Is_Atomic (E) and then not Is_Atomic (T)) or else (Is_Volatile (E) and then not Is_Volatile (T)) then Error_Msg_N ("cannot take reference to Atomic/Volatile object", N); end if; end if; -- Carry on with normal processing Acc_Type := Create_Itype (E_Allocator_Type, N); Set_Etype (Acc_Type, Acc_Type); Set_Directly_Designated_Type (Acc_Type, Etype (P)); Set_Etype (N, Acc_Type); end Analyze_Reference; -------------------------------- -- Analyze_Selected_Component -- -------------------------------- -- Prefix is a record type or a task or protected type. In the -- later case, the selector must denote a visible entry. procedure Analyze_Selected_Component (N : Node_Id) is Name : constant Node_Id := Prefix (N); Sel : constant Node_Id := Selector_Name (N); Act_Decl : Node_Id; Comp : Entity_Id; Has_Candidate : Boolean := False; In_Scope : Boolean; Parent_N : Node_Id; Pent : Entity_Id := Empty; Prefix_Type : Entity_Id; Type_To_Use : Entity_Id; -- In most cases this is the Prefix_Type, but if the Prefix_Type is -- a class-wide type, we use its root type, whose components are -- present in the class-wide type. function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean; -- It is known that the parent of N denotes a subprogram call. Comp -- is an overloadable component of the concurrent type of the prefix. -- Determine whether all formals of the parent of N and Comp are mode -- conformant. If the parent node is not analyzed yet it may be an -- indexed component rather than a function call. ------------------------------ -- Has_Mode_Conformant_Spec -- ------------------------------ function Has_Mode_Conformant_Spec (Comp : Entity_Id) return Boolean is Comp_Param : Entity_Id; Param : Node_Id; Param_Typ : Entity_Id; begin Comp_Param := First_Formal (Comp); if Nkind (Parent (N)) = N_Indexed_Component then Param := First (Expressions (Parent (N))); else Param := First (Parameter_Associations (Parent (N))); end if; while Present (Comp_Param) and then Present (Param) loop Param_Typ := Find_Parameter_Type (Param); if Present (Param_Typ) and then not Conforming_Types (Etype (Comp_Param), Param_Typ, Mode_Conformant) then return False; end if; Next_Formal (Comp_Param); Next (Param); end loop; -- One of the specs has additional formals if Present (Comp_Param) or else Present (Param) then return False; end if; return True; end Has_Mode_Conformant_Spec; -- Start of processing for Analyze_Selected_Component begin Set_Etype (N, Any_Type); if Is_Overloaded (Name) then Analyze_Overloaded_Selected_Component (N); return; elsif Etype (Name) = Any_Type then Set_Entity (Sel, Any_Id); Set_Etype (Sel, Any_Type); return; else Prefix_Type := Etype (Name); end if; if Is_Access_Type (Prefix_Type) then -- A RACW object can never be used as prefix of a selected -- component since that means it is dereferenced without -- being a controlling operand of a dispatching operation -- (RM E.2.2(16/1)). Before reporting an error, we must check -- whether this is actually a dispatching call in prefix form. if Is_Remote_Access_To_Class_Wide_Type (Prefix_Type) and then Comes_From_Source (N) then if Try_Object_Operation (N) then return; else Error_Msg_N ("invalid dereference of a remote access-to-class-wide value", N); end if; -- Normal case of selected component applied to access type else Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); if Is_Entity_Name (Name) then Pent := Entity (Name); elsif Nkind (Name) = N_Selected_Component and then Is_Entity_Name (Selector_Name (Name)) then Pent := Entity (Selector_Name (Name)); end if; Prefix_Type := Process_Implicit_Dereference_Prefix (Pent, Name); end if; -- If we have an explicit dereference of a remote access-to-class-wide -- value, then issue an error (see RM-E.2.2(16/1)). However we first -- have to check for the case of a prefix that is a controlling operand -- of a prefixed dispatching call, as the dereference is legal in that -- case. Normally this condition is checked in Validate_Remote_Access_ -- To_Class_Wide_Type, but we have to defer the checking for selected -- component prefixes because of the prefixed dispatching call case. -- Note that implicit dereferences are checked for this just above. elsif Nkind (Name) = N_Explicit_Dereference and then Is_Remote_Access_To_Class_Wide_Type (Etype (Prefix (Name))) and then Comes_From_Source (N) then if Try_Object_Operation (N) then return; else Error_Msg_N ("invalid dereference of a remote access-to-class-wide value", N); end if; end if; -- (Ada 2005): if the prefix is the limited view of a type, and -- the context already includes the full view, use the full view -- in what follows, either to retrieve a component of to find -- a primitive operation. If the prefix is an explicit dereference, -- set the type of the prefix to reflect this transformation. -- If the non-limited view is itself an incomplete type, get the -- full view if available. if Is_Incomplete_Type (Prefix_Type) and then From_With_Type (Prefix_Type) and then Present (Non_Limited_View (Prefix_Type)) then Prefix_Type := Get_Full_View (Non_Limited_View (Prefix_Type)); if Nkind (N) = N_Explicit_Dereference then Set_Etype (Prefix (N), Prefix_Type); end if; elsif Ekind (Prefix_Type) = E_Class_Wide_Type and then From_With_Type (Prefix_Type) and then Present (Non_Limited_View (Etype (Prefix_Type))) then Prefix_Type := Class_Wide_Type (Non_Limited_View (Etype (Prefix_Type))); if Nkind (N) = N_Explicit_Dereference then Set_Etype (Prefix (N), Prefix_Type); end if; end if; if Ekind (Prefix_Type) = E_Private_Subtype then Prefix_Type := Base_Type (Prefix_Type); end if; Type_To_Use := Prefix_Type; -- For class-wide types, use the entity list of the root type. This -- indirection is specially important for private extensions because -- only the root type get switched (not the class-wide type). if Is_Class_Wide_Type (Prefix_Type) then Type_To_Use := Root_Type (Prefix_Type); end if; Comp := First_Entity (Type_To_Use); -- If the selector has an original discriminant, the node appears in -- an instance. Replace the discriminant with the corresponding one -- in the current discriminated type. For nested generics, this must -- be done transitively, so note the new original discriminant. if Nkind (Sel) = N_Identifier and then Present (Original_Discriminant (Sel)) then Comp := Find_Corresponding_Discriminant (Sel, Prefix_Type); -- Mark entity before rewriting, for completeness and because -- subsequent semantic checks might examine the original node. Set_Entity (Sel, Comp); Rewrite (Selector_Name (N), New_Occurrence_Of (Comp, Sloc (N))); Set_Original_Discriminant (Selector_Name (N), Comp); Set_Etype (N, Etype (Comp)); if Is_Access_Type (Etype (Name)) then Insert_Explicit_Dereference (Name); Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); end if; elsif Is_Record_Type (Prefix_Type) then -- Find component with given name while Present (Comp) loop if Chars (Comp) = Chars (Sel) and then Is_Visible_Component (Comp) then Set_Entity_With_Style_Check (Sel, Comp); Set_Etype (Sel, Etype (Comp)); if Ekind (Comp) = E_Discriminant then if Is_Unchecked_Union (Base_Type (Prefix_Type)) then Error_Msg_N ("cannot reference discriminant of Unchecked_Union", Sel); end if; if Is_Generic_Type (Prefix_Type) or else Is_Generic_Type (Root_Type (Prefix_Type)) then Set_Original_Discriminant (Sel, Comp); end if; end if; -- Resolve the prefix early otherwise it is not possible to -- build the actual subtype of the component: it may need -- to duplicate this prefix and duplication is only allowed -- on fully resolved expressions. Resolve (Name); -- Ada 2005 (AI-50217): Check wrong use of incomplete types or -- subtypes in a package specification. -- Example: -- limited with Pkg; -- package Pkg is -- type Acc_Inc is access Pkg.T; -- X : Acc_Inc; -- N : Natural := X.all.Comp; -- ERROR, limited view -- end Pkg; -- Comp is not visible if Nkind (Name) = N_Explicit_Dereference and then From_With_Type (Etype (Prefix (Name))) and then not Is_Potentially_Use_Visible (Etype (Name)) and then Nkind (Parent (Cunit_Entity (Current_Sem_Unit))) = N_Package_Specification then Error_Msg_NE ("premature usage of incomplete}", Prefix (Name), Etype (Prefix (Name))); end if; -- We never need an actual subtype for the case of a selection -- for a indexed component of a non-packed array, since in -- this case gigi generates all the checks and can find the -- necessary bounds information. -- We also do not need an actual subtype for the case of -- a first, last, length, or range attribute applied to a -- non-packed array, since gigi can again get the bounds in -- these cases (gigi cannot handle the packed case, since it -- has the bounds of the packed array type, not the original -- bounds of the type). However, if the prefix is itself a -- selected component, as in a.b.c (i), gigi may regard a.b.c -- as a dynamic-sized temporary, so we do generate an actual -- subtype for this case. Parent_N := Parent (N); if not Is_Packed (Etype (Comp)) and then ((Nkind (Parent_N) = N_Indexed_Component and then Nkind (Name) /= N_Selected_Component) or else (Nkind (Parent_N) = N_Attribute_Reference and then (Attribute_Name (Parent_N) = Name_First or else Attribute_Name (Parent_N) = Name_Last or else Attribute_Name (Parent_N) = Name_Length or else Attribute_Name (Parent_N) = Name_Range))) then Set_Etype (N, Etype (Comp)); -- If full analysis is not enabled, we do not generate an -- actual subtype, because in the absence of expansion -- reference to a formal of a protected type, for example, -- will not be properly transformed, and will lead to -- out-of-scope references in gigi. -- In all other cases, we currently build an actual subtype. -- It seems likely that many of these cases can be avoided, -- but right now, the front end makes direct references to the -- bounds (e.g. in generating a length check), and if we do -- not make an actual subtype, we end up getting a direct -- reference to a discriminant, which will not do. elsif Full_Analysis then Act_Decl := Build_Actual_Subtype_Of_Component (Etype (Comp), N); Insert_Action (N, Act_Decl); if No (Act_Decl) then Set_Etype (N, Etype (Comp)); else -- Component type depends on discriminants. Enter the -- main attributes of the subtype. declare Subt : constant Entity_Id := Defining_Identifier (Act_Decl); begin Set_Etype (Subt, Base_Type (Etype (Comp))); Set_Ekind (Subt, Ekind (Etype (Comp))); Set_Etype (N, Subt); end; end if; -- If Full_Analysis not enabled, just set the Etype else Set_Etype (N, Etype (Comp)); end if; return; end if; -- If the prefix is a private extension, check only the visible -- components of the partial view. This must include the tag, -- which can appear in expanded code in a tag check. if Ekind (Type_To_Use) = E_Record_Type_With_Private and then Chars (Selector_Name (N)) /= Name_uTag then exit when Comp = Last_Entity (Type_To_Use); end if; Next_Entity (Comp); end loop; -- Ada 2005 (AI-252): The selected component can be interpreted as -- a prefixed view of a subprogram. Depending on the context, this is -- either a name that can appear in a renaming declaration, or part -- of an enclosing call given in prefix form. -- Ada 2005 (AI05-0030): In the case of dispatching requeue, the -- selected component should resolve to a name. if Ada_Version >= Ada_05 and then Is_Tagged_Type (Prefix_Type) and then not Is_Concurrent_Type (Prefix_Type) then if Nkind (Parent (N)) = N_Generic_Association or else Nkind (Parent (N)) = N_Requeue_Statement or else Nkind (Parent (N)) = N_Subprogram_Renaming_Declaration then if Find_Primitive_Operation (N) then return; end if; elsif Try_Object_Operation (N) then return; end if; -- If the transformation fails, it will be necessary to redo the -- analysis with all errors enabled, to indicate candidate -- interpretations and reasons for each failure ??? end if; elsif Is_Private_Type (Prefix_Type) then -- Allow access only to discriminants of the type. If the type has -- no full view, gigi uses the parent type for the components, so we -- do the same here. if No (Full_View (Prefix_Type)) then Type_To_Use := Root_Type (Base_Type (Prefix_Type)); Comp := First_Entity (Type_To_Use); end if; while Present (Comp) loop if Chars (Comp) = Chars (Sel) then if Ekind (Comp) = E_Discriminant then Set_Entity_With_Style_Check (Sel, Comp); Generate_Reference (Comp, Sel); Set_Etype (Sel, Etype (Comp)); Set_Etype (N, Etype (Comp)); if Is_Generic_Type (Prefix_Type) or else Is_Generic_Type (Root_Type (Prefix_Type)) then Set_Original_Discriminant (Sel, Comp); end if; -- Before declaring an error, check whether this is tagged -- private type and a call to a primitive operation. elsif Ada_Version >= Ada_05 and then Is_Tagged_Type (Prefix_Type) and then Try_Object_Operation (N) then return; else Error_Msg_NE ("invisible selector for }", N, First_Subtype (Prefix_Type)); Set_Entity (Sel, Any_Id); Set_Etype (N, Any_Type); end if; return; end if; Next_Entity (Comp); end loop; elsif Is_Concurrent_Type (Prefix_Type) then -- Find visible operation with given name. For a protected type, -- the possible candidates are discriminants, entries or protected -- procedures. For a task type, the set can only include entries or -- discriminants if the task type is not an enclosing scope. If it -- is an enclosing scope (e.g. in an inner task) then all entities -- are visible, but the prefix must denote the enclosing scope, i.e. -- can only be a direct name or an expanded name. Set_Etype (Sel, Any_Type); In_Scope := In_Open_Scopes (Prefix_Type); while Present (Comp) loop if Chars (Comp) = Chars (Sel) then if Is_Overloadable (Comp) then Add_One_Interp (Sel, Comp, Etype (Comp)); -- If the prefix is tagged, the correct interpretation may -- lie in the primitive or class-wide operations of the -- type. Perform a simple conformance check to determine -- whether Try_Object_Operation should be invoked even if -- a visible entity is found. if Is_Tagged_Type (Prefix_Type) and then Nkind_In (Parent (N), N_Procedure_Call_Statement, N_Function_Call, N_Indexed_Component) and then Has_Mode_Conformant_Spec (Comp) then Has_Candidate := True; end if; elsif Ekind (Comp) = E_Discriminant or else Ekind (Comp) = E_Entry_Family or else (In_Scope and then Is_Entity_Name (Name)) then Set_Entity_With_Style_Check (Sel, Comp); Generate_Reference (Comp, Sel); else goto Next_Comp; end if; Set_Etype (Sel, Etype (Comp)); Set_Etype (N, Etype (Comp)); if Ekind (Comp) = E_Discriminant then Set_Original_Discriminant (Sel, Comp); end if; -- For access type case, introduce explicit dereference for -- more uniform treatment of entry calls. if Is_Access_Type (Etype (Name)) then Insert_Explicit_Dereference (Name); Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); end if; end if; <<Next_Comp>> Next_Entity (Comp); exit when not In_Scope and then Comp = First_Private_Entity (Base_Type (Prefix_Type)); end loop; -- If there is no visible entity with the given name or none of the -- visible entities are plausible interpretations, check whether -- there is some other primitive operation with that name. if Ada_Version >= Ada_05 and then Is_Tagged_Type (Prefix_Type) then if (Etype (N) = Any_Type or else not Has_Candidate) and then Try_Object_Operation (N) then return; -- If the context is not syntactically a procedure call, it -- may be a call to a primitive function declared outside of -- the synchronized type. -- If the context is a procedure call, there might still be -- an overloading between an entry and a primitive procedure -- declared outside of the synchronized type, called in prefix -- notation. This is harder to disambiguate because in one case -- the controlling formal is implicit ??? elsif Nkind (Parent (N)) /= N_Procedure_Call_Statement and then Nkind (Parent (N)) /= N_Indexed_Component and then Try_Object_Operation (N) then return; end if; end if; Set_Is_Overloaded (N, Is_Overloaded (Sel)); else -- Invalid prefix Error_Msg_NE ("invalid prefix in selected component&", N, Sel); end if; -- If N still has no type, the component is not defined in the prefix if Etype (N) = Any_Type then -- If the prefix is a single concurrent object, use its name in the -- error message, rather than that of its anonymous type. if Is_Concurrent_Type (Prefix_Type) and then Is_Internal_Name (Chars (Prefix_Type)) and then not Is_Derived_Type (Prefix_Type) and then Is_Entity_Name (Name) then Error_Msg_Node_2 := Entity (Name); Error_Msg_NE ("no selector& for&", N, Sel); Check_Misspelled_Selector (Type_To_Use, Sel); elsif Is_Generic_Type (Prefix_Type) and then Ekind (Prefix_Type) = E_Record_Type_With_Private and then Prefix_Type /= Etype (Prefix_Type) and then Is_Record_Type (Etype (Prefix_Type)) then -- If this is a derived formal type, the parent may have -- different visibility at this point. Try for an inherited -- component before reporting an error. Set_Etype (Prefix (N), Etype (Prefix_Type)); Analyze_Selected_Component (N); return; elsif Ekind (Prefix_Type) = E_Record_Subtype_With_Private and then Is_Generic_Actual_Type (Prefix_Type) and then Present (Full_View (Prefix_Type)) then -- Similarly, if this the actual for a formal derived type, the -- component inherited from the generic parent may not be visible -- in the actual, but the selected component is legal. declare Comp : Entity_Id; begin Comp := First_Component (Generic_Parent_Type (Parent (Prefix_Type))); while Present (Comp) loop if Chars (Comp) = Chars (Sel) then Set_Entity_With_Style_Check (Sel, Comp); Set_Etype (Sel, Etype (Comp)); Set_Etype (N, Etype (Comp)); return; end if; Next_Component (Comp); end loop; pragma Assert (Etype (N) /= Any_Type); end; else if Ekind (Prefix_Type) = E_Record_Subtype then -- Check whether this is a component of the base type -- which is absent from a statically constrained subtype. -- This will raise constraint error at run-time, but is -- not a compile-time error. When the selector is illegal -- for base type as well fall through and generate a -- compilation error anyway. Comp := First_Component (Base_Type (Prefix_Type)); while Present (Comp) loop if Chars (Comp) = Chars (Sel) and then Is_Visible_Component (Comp) then Set_Entity_With_Style_Check (Sel, Comp); Generate_Reference (Comp, Sel); Set_Etype (Sel, Etype (Comp)); Set_Etype (N, Etype (Comp)); -- Emit appropriate message. Gigi will replace the -- node subsequently with the appropriate Raise. Apply_Compile_Time_Constraint_Error (N, "component not present in }?", CE_Discriminant_Check_Failed, Ent => Prefix_Type, Rep => False); Set_Raises_Constraint_Error (N); return; end if; Next_Component (Comp); end loop; end if; Error_Msg_Node_2 := First_Subtype (Prefix_Type); Error_Msg_NE ("no selector& for}", N, Sel); Check_Misspelled_Selector (Type_To_Use, Sel); end if; Set_Entity (Sel, Any_Id); Set_Etype (Sel, Any_Type); end if; end Analyze_Selected_Component; --------------------------- -- Analyze_Short_Circuit -- --------------------------- procedure Analyze_Short_Circuit (N : Node_Id) is L : constant Node_Id := Left_Opnd (N); R : constant Node_Id := Right_Opnd (N); Ind : Interp_Index; It : Interp; begin Analyze_Expression (L); Analyze_Expression (R); Set_Etype (N, Any_Type); if not Is_Overloaded (L) then if Root_Type (Etype (L)) = Standard_Boolean and then Has_Compatible_Type (R, Etype (L)) then Add_One_Interp (N, Etype (L), Etype (L)); end if; else Get_First_Interp (L, Ind, It); while Present (It.Typ) loop if Root_Type (It.Typ) = Standard_Boolean and then Has_Compatible_Type (R, It.Typ) then Add_One_Interp (N, It.Typ, It.Typ); end if; Get_Next_Interp (Ind, It); end loop; end if; -- Here we have failed to find an interpretation. Clearly we know that -- it is not the case that both operands can have an interpretation of -- Boolean, but this is by far the most likely intended interpretation. -- So we simply resolve both operands as Booleans, and at least one of -- these resolutions will generate an error message, and we do not need -- to give another error message on the short circuit operation itself. if Etype (N) = Any_Type then Resolve (L, Standard_Boolean); Resolve (R, Standard_Boolean); Set_Etype (N, Standard_Boolean); end if; end Analyze_Short_Circuit; ------------------- -- Analyze_Slice -- ------------------- procedure Analyze_Slice (N : Node_Id) is P : constant Node_Id := Prefix (N); D : constant Node_Id := Discrete_Range (N); Array_Type : Entity_Id; procedure Analyze_Overloaded_Slice; -- If the prefix is overloaded, select those interpretations that -- yield a one-dimensional array type. ------------------------------ -- Analyze_Overloaded_Slice -- ------------------------------ procedure Analyze_Overloaded_Slice is I : Interp_Index; It : Interp; Typ : Entity_Id; begin Set_Etype (N, Any_Type); Get_First_Interp (P, I, It); while Present (It.Nam) loop Typ := It.Typ; if Is_Access_Type (Typ) then Typ := Designated_Type (Typ); Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); end if; if Is_Array_Type (Typ) and then Number_Dimensions (Typ) = 1 and then Has_Compatible_Type (D, Etype (First_Index (Typ))) then Add_One_Interp (N, Typ, Typ); end if; Get_Next_Interp (I, It); end loop; if Etype (N) = Any_Type then Error_Msg_N ("expect array type in prefix of slice", N); end if; end Analyze_Overloaded_Slice; -- Start of processing for Analyze_Slice begin Analyze (P); Analyze (D); if Is_Overloaded (P) then Analyze_Overloaded_Slice; else Array_Type := Etype (P); Set_Etype (N, Any_Type); if Is_Access_Type (Array_Type) then Array_Type := Designated_Type (Array_Type); Error_Msg_NW (Warn_On_Dereference, "?implicit dereference", N); end if; if not Is_Array_Type (Array_Type) then Wrong_Type (P, Any_Array); elsif Number_Dimensions (Array_Type) > 1 then Error_Msg_N ("type is not one-dimensional array in slice prefix", N); elsif not Has_Compatible_Type (D, Etype (First_Index (Array_Type))) then Wrong_Type (D, Etype (First_Index (Array_Type))); else Set_Etype (N, Array_Type); end if; end if; end Analyze_Slice; ----------------------------- -- Analyze_Type_Conversion -- ----------------------------- procedure Analyze_Type_Conversion (N : Node_Id) is Expr : constant Node_Id := Expression (N); T : Entity_Id; begin -- Check if the expression is a function call for which we need to -- adjust a SCIL dispatching node. if Generate_SCIL and then Nkind (Expr) = N_Function_Call then Adjust_SCIL_Node (N, Expr); end if; -- If Conversion_OK is set, then the Etype is already set, and the -- only processing required is to analyze the expression. This is -- used to construct certain "illegal" conversions which are not -- allowed by Ada semantics, but can be handled OK by Gigi, see -- Sinfo for further details. if Conversion_OK (N) then Analyze (Expr); return; end if; -- Otherwise full type analysis is required, as well as some semantic -- checks to make sure the argument of the conversion is appropriate. Find_Type (Subtype_Mark (N)); T := Entity (Subtype_Mark (N)); Set_Etype (N, T); Check_Fully_Declared (T, N); Analyze_Expression (Expr); Validate_Remote_Type_Type_Conversion (N); -- Only remaining step is validity checks on the argument. These -- are skipped if the conversion does not come from the source. if not Comes_From_Source (N) then return; -- If there was an error in a generic unit, no need to replicate the -- error message. Conversely, constant-folding in the generic may -- transform the argument of a conversion into a string literal, which -- is legal. Therefore the following tests are not performed in an -- instance. elsif In_Instance then return; elsif Nkind (Expr) = N_Null then Error_Msg_N ("argument of conversion cannot be null", N); Error_Msg_N ("\use qualified expression instead", N); Set_Etype (N, Any_Type); elsif Nkind (Expr) = N_Aggregate then Error_Msg_N ("argument of conversion cannot be aggregate", N); Error_Msg_N ("\use qualified expression instead", N); elsif Nkind (Expr) = N_Allocator then Error_Msg_N ("argument of conversion cannot be an allocator", N); Error_Msg_N ("\use qualified expression instead", N); elsif Nkind (Expr) = N_String_Literal then Error_Msg_N ("argument of conversion cannot be string literal", N); Error_Msg_N ("\use qualified expression instead", N); elsif Nkind (Expr) = N_Character_Literal then if Ada_Version = Ada_83 then Resolve (Expr, T); else Error_Msg_N ("argument of conversion cannot be character literal", N); Error_Msg_N ("\use qualified expression instead", N); end if; elsif Nkind (Expr) = N_Attribute_Reference and then (Attribute_Name (Expr) = Name_Access or else Attribute_Name (Expr) = Name_Unchecked_Access or else Attribute_Name (Expr) = Name_Unrestricted_Access) then Error_Msg_N ("argument of conversion cannot be access", N); Error_Msg_N ("\use qualified expression instead", N); end if; end Analyze_Type_Conversion; ---------------------- -- Analyze_Unary_Op -- ---------------------- procedure Analyze_Unary_Op (N : Node_Id) is R : constant Node_Id := Right_Opnd (N); Op_Id : Entity_Id := Entity (N); begin Set_Etype (N, Any_Type); Candidate_Type := Empty; Analyze_Expression (R); if Present (Op_Id) then if Ekind (Op_Id) = E_Operator then Find_Unary_Types (R, Op_Id, N); else Add_One_Interp (N, Op_Id, Etype (Op_Id)); end if; else Op_Id := Get_Name_Entity_Id (Chars (N)); while Present (Op_Id) loop if Ekind (Op_Id) = E_Operator then if No (Next_Entity (First_Entity (Op_Id))) then Find_Unary_Types (R, Op_Id, N); end if; elsif Is_Overloadable (Op_Id) then Analyze_User_Defined_Unary_Op (N, Op_Id); end if; Op_Id := Homonym (Op_Id); end loop; end if; Operator_Check (N); end Analyze_Unary_Op; ---------------------------------- -- Analyze_Unchecked_Expression -- ---------------------------------- procedure Analyze_Unchecked_Expression (N : Node_Id) is begin Analyze (Expression (N), Suppress => All_Checks); Set_Etype (N, Etype (Expression (N))); Save_Interps (Expression (N), N); end Analyze_Unchecked_Expression; --------------------------------------- -- Analyze_Unchecked_Type_Conversion -- --------------------------------------- procedure Analyze_Unchecked_Type_Conversion (N : Node_Id) is begin Find_Type (Subtype_Mark (N)); Analyze_Expression (Expression (N)); Set_Etype (N, Entity (Subtype_Mark (N))); end Analyze_Unchecked_Type_Conversion; ------------------------------------ -- Analyze_User_Defined_Binary_Op -- ------------------------------------ procedure Analyze_User_Defined_Binary_Op (N : Node_Id; Op_Id : Entity_Id) is begin -- Only do analysis if the operator Comes_From_Source, since otherwise -- the operator was generated by the expander, and all such operators -- always refer to the operators in package Standard. if Comes_From_Source (N) then declare F1 : constant Entity_Id := First_Formal (Op_Id); F2 : constant Entity_Id := Next_Formal (F1); begin -- Verify that Op_Id is a visible binary function. Note that since -- we know Op_Id is overloaded, potentially use visible means use -- visible for sure (RM 9.4(11)). if Ekind (Op_Id) = E_Function and then Present (F2) and then (Is_Immediately_Visible (Op_Id) or else Is_Potentially_Use_Visible (Op_Id)) and then Has_Compatible_Type (Left_Opnd (N), Etype (F1)) and then Has_Compatible_Type (Right_Opnd (N), Etype (F2)) then Add_One_Interp (N, Op_Id, Etype (Op_Id)); -- If the left operand is overloaded, indicate that the -- current type is a viable candidate. This is redundant -- in most cases, but for equality and comparison operators -- where the context does not impose a type on the operands, -- setting the proper type is necessary to avoid subsequent -- ambiguities during resolution, when both user-defined and -- predefined operators may be candidates. if Is_Overloaded (Left_Opnd (N)) then Set_Etype (Left_Opnd (N), Etype (F1)); end if; if Debug_Flag_E then Write_Str ("user defined operator "); Write_Name (Chars (Op_Id)); Write_Str (" on node "); Write_Int (Int (N)); Write_Eol; end if; end if; end; end if; end Analyze_User_Defined_Binary_Op; ----------------------------------- -- Analyze_User_Defined_Unary_Op -- ----------------------------------- procedure Analyze_User_Defined_Unary_Op (N : Node_Id; Op_Id : Entity_Id) is begin -- Only do analysis if the operator Comes_From_Source, since otherwise -- the operator was generated by the expander, and all such operators -- always refer to the operators in package Standard. if Comes_From_Source (N) then declare F : constant Entity_Id := First_Formal (Op_Id); begin -- Verify that Op_Id is a visible unary function. Note that since -- we know Op_Id is overloaded, potentially use visible means use -- visible for sure (RM 9.4(11)). if Ekind (Op_Id) = E_Function and then No (Next_Formal (F)) and then (Is_Immediately_Visible (Op_Id) or else Is_Potentially_Use_Visible (Op_Id)) and then Has_Compatible_Type (Right_Opnd (N), Etype (F)) then Add_One_Interp (N, Op_Id, Etype (Op_Id)); end if; end; end if; end Analyze_User_Defined_Unary_Op; --------------------------- -- Check_Arithmetic_Pair -- --------------------------- procedure Check_Arithmetic_Pair (T1, T2 : Entity_Id; Op_Id : Entity_Id; N : Node_Id) is Op_Name : constant Name_Id := Chars (Op_Id); function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean; -- Check whether the fixed-point type Typ has a user-defined operator -- (multiplication or division) that should hide the corresponding -- predefined operator. Used to implement Ada 2005 AI-264, to make -- such operators more visible and therefore useful. -- If the name of the operation is an expanded name with prefix -- Standard, the predefined universal fixed operator is available, -- as specified by AI-420 (RM 4.5.5 (19.1/2)). function Specific_Type (T1, T2 : Entity_Id) return Entity_Id; -- Get specific type (i.e. non-universal type if there is one) ------------------ -- Has_Fixed_Op -- ------------------ function Has_Fixed_Op (Typ : Entity_Id; Op : Entity_Id) return Boolean is Bas : constant Entity_Id := Base_Type (Typ); Ent : Entity_Id; F1 : Entity_Id; F2 : Entity_Id; begin -- If the universal_fixed operation is given explicitly the rule -- concerning primitive operations of the type do not apply. if Nkind (N) = N_Function_Call and then Nkind (Name (N)) = N_Expanded_Name and then Entity (Prefix (Name (N))) = Standard_Standard then return False; end if; -- The operation is treated as primitive if it is declared in the -- same scope as the type, and therefore on the same entity chain. Ent := Next_Entity (Typ); while Present (Ent) loop if Chars (Ent) = Chars (Op) then F1 := First_Formal (Ent); F2 := Next_Formal (F1); -- The operation counts as primitive if either operand or -- result are of the given base type, and both operands are -- fixed point types. if (Base_Type (Etype (F1)) = Bas and then Is_Fixed_Point_Type (Etype (F2))) or else (Base_Type (Etype (F2)) = Bas and then Is_Fixed_Point_Type (Etype (F1))) or else (Base_Type (Etype (Ent)) = Bas and then Is_Fixed_Point_Type (Etype (F1)) and then Is_Fixed_Point_Type (Etype (F2))) then return True; end if; end if; Next_Entity (Ent); end loop; return False; end Has_Fixed_Op; ------------------- -- Specific_Type -- ------------------- function Specific_Type (T1, T2 : Entity_Id) return Entity_Id is begin if T1 = Universal_Integer or else T1 = Universal_Real then return Base_Type (T2); else return Base_Type (T1); end if; end Specific_Type; -- Start of processing for Check_Arithmetic_Pair begin if Op_Name = Name_Op_Add or else Op_Name = Name_Op_Subtract then if Is_Numeric_Type (T1) and then Is_Numeric_Type (T2) and then (Covers (T1 => T1, T2 => T2) or else Covers (T1 => T2, T2 => T1)) then Add_One_Interp (N, Op_Id, Specific_Type (T1, T2)); end if; elsif Op_Name = Name_Op_Multiply or else Op_Name = Name_Op_Divide then if Is_Fixed_Point_Type (T1) and then (Is_Fixed_Point_Type (T2) or else T2 = Universal_Real) then -- If Treat_Fixed_As_Integer is set then the Etype is already set -- and no further processing is required (this is the case of an -- operator constructed by Exp_Fixd for a fixed point operation) -- Otherwise add one interpretation with universal fixed result -- If the operator is given in functional notation, it comes -- from source and Fixed_As_Integer cannot apply. if (Nkind (N) not in N_Op or else not Treat_Fixed_As_Integer (N)) and then (not Has_Fixed_Op (T1, Op_Id) or else Nkind (Parent (N)) = N_Type_Conversion) then Add_One_Interp (N, Op_Id, Universal_Fixed); end if; elsif Is_Fixed_Point_Type (T2) and then (Nkind (N) not in N_Op or else not Treat_Fixed_As_Integer (N)) and then T1 = Universal_Real and then (not Has_Fixed_Op (T1, Op_Id) or else Nkind (Parent (N)) = N_Type_Conversion) then Add_One_Interp (N, Op_Id, Universal_Fixed); elsif Is_Numeric_Type (T1) and then Is_Numeric_Type (T2) and then (Covers (T1 => T1, T2 => T2) or else Covers (T1 => T2, T2 => T1)) then Add_One_Interp (N, Op_Id, Specific_Type (T1, T2)); elsif Is_Fixed_Point_Type (T1) and then (Base_Type (T2) = Base_Type (Standard_Integer) or else T2 = Universal_Integer) then Add_One_Interp (N, Op_Id, T1); elsif T2 = Universal_Real and then Base_Type (T1) = Base_Type (Standard_Integer) and then Op_Name = Name_Op_Multiply then Add_One_Interp (N, Op_Id, Any_Fixed); elsif T1 = Universal_Real and then Base_Type (T2) = Base_Type (Standard_Integer) then Add_One_Interp (N, Op_Id, Any_Fixed); elsif Is_Fixed_Point_Type (T2) and then (Base_Type (T1) = Base_Type (Standard_Integer) or else T1 = Universal_Integer) and then Op_Name = Name_Op_Multiply then Add_One_Interp (N, Op_Id, T2); elsif T1 = Universal_Real and then T2 = Universal_Integer then Add_One_Interp (N, Op_Id, T1); elsif T2 = Universal_Real and then T1 = Universal_Integer and then Op_Name = Name_Op_Multiply then Add_One_Interp (N, Op_Id, T2); end if; elsif Op_Name = Name_Op_Mod or else Op_Name = Name_Op_Rem then -- Note: The fixed-point operands case with Treat_Fixed_As_Integer -- set does not require any special processing, since the Etype is -- already set (case of operation constructed by Exp_Fixed). if Is_Integer_Type (T1) and then (Covers (T1 => T1, T2 => T2) or else Covers (T1 => T2, T2 => T1)) then Add_One_Interp (N, Op_Id, Specific_Type (T1, T2)); end if; elsif Op_Name = Name_Op_Expon then if Is_Numeric_Type (T1) and then not Is_Fixed_Point_Type (T1) and then (Base_Type (T2) = Base_Type (Standard_Integer) or else T2 = Universal_Integer) then Add_One_Interp (N, Op_Id, Base_Type (T1)); end if; else pragma Assert (Nkind (N) in N_Op_Shift); -- If not one of the predefined operators, the node may be one -- of the intrinsic functions. Its kind is always specific, and -- we can use it directly, rather than the name of the operation. if Is_Integer_Type (T1) and then (Base_Type (T2) = Base_Type (Standard_Integer) or else T2 = Universal_Integer) then Add_One_Interp (N, Op_Id, Base_Type (T1)); end if; end if; end Check_Arithmetic_Pair; ------------------------------- -- Check_Misspelled_Selector -- ------------------------------- procedure Check_Misspelled_Selector (Prefix : Entity_Id; Sel : Node_Id) is Max_Suggestions : constant := 2; Nr_Of_Suggestions : Natural := 0; Suggestion_1 : Entity_Id := Empty; Suggestion_2 : Entity_Id := Empty; Comp : Entity_Id; begin -- All the components of the prefix of selector Sel are matched -- against Sel and a count is maintained of possible misspellings. -- When at the end of the analysis there are one or two (not more!) -- possible misspellings, these misspellings will be suggested as -- possible correction. if not (Is_Private_Type (Prefix) or else Is_Record_Type (Prefix)) then -- Concurrent types should be handled as well ??? return; end if; Comp := First_Entity (Prefix); while Nr_Of_Suggestions <= Max_Suggestions and then Present (Comp) loop if Is_Visible_Component (Comp) then if Is_Bad_Spelling_Of (Chars (Comp), Chars (Sel)) then Nr_Of_Suggestions := Nr_Of_Suggestions + 1; case Nr_Of_Suggestions is when 1 => Suggestion_1 := Comp; when 2 => Suggestion_2 := Comp; when others => exit; end case; end if; end if; Comp := Next_Entity (Comp); end loop; -- Report at most two suggestions if Nr_Of_Suggestions = 1 then Error_Msg_NE -- CODEFIX ("\possible misspelling of&", Sel, Suggestion_1); elsif Nr_Of_Suggestions = 2 then Error_Msg_Node_2 := Suggestion_2; Error_Msg_NE -- CODEFIX ("\possible misspelling of& or&", Sel, Suggestion_1); end if; end Check_Misspelled_Selector; ---------------------- -- Defined_In_Scope -- ---------------------- function Defined_In_Scope (T : Entity_Id; S : Entity_Id) return Boolean is S1 : constant Entity_Id := Scope (Base_Type (T)); begin return S1 = S or else (S1 = System_Aux_Id and then S = Scope (S1)); end Defined_In_Scope; ------------------- -- Diagnose_Call -- ------------------- procedure Diagnose_Call (N : Node_Id; Nam : Node_Id) is Actual : Node_Id; X : Interp_Index; It : Interp; Err_Mode : Boolean; New_Nam : Node_Id; Void_Interp_Seen : Boolean := False; Success : Boolean; pragma Warnings (Off, Boolean); begin if Ada_Version >= Ada_05 then Actual := First_Actual (N); while Present (Actual) loop -- Ada 2005 (AI-50217): Post an error in case of premature -- usage of an entity from the limited view. if not Analyzed (Etype (Actual)) and then From_With_Type (Etype (Actual)) then Error_Msg_Qual_Level := 1; Error_Msg_NE ("missing with_clause for scope of imported type&", Actual, Etype (Actual)); Error_Msg_Qual_Level := 0; end if; Next_Actual (Actual); end loop; end if; -- Analyze each candidate call again, with full error reporting -- for each. Error_Msg_N ("no candidate interpretations match the actuals:!", Nam); Err_Mode := All_Errors_Mode; All_Errors_Mode := True; -- If this is a call to an operation of a concurrent type, -- the failed interpretations have been removed from the -- name. Recover them to provide full diagnostics. if Nkind (Parent (Nam)) = N_Selected_Component then Set_Entity (Nam, Empty); New_Nam := New_Copy_Tree (Parent (Nam)); Set_Is_Overloaded (New_Nam, False); Set_Is_Overloaded (Selector_Name (New_Nam), False); Set_Parent (New_Nam, Parent (Parent (Nam))); Analyze_Selected_Component (New_Nam); Get_First_Interp (Selector_Name (New_Nam), X, It); else Get_First_Interp (Nam, X, It); end if; while Present (It.Nam) loop if Etype (It.Nam) = Standard_Void_Type then Void_Interp_Seen := True; end if; Analyze_One_Call (N, It.Nam, True, Success); Get_Next_Interp (X, It); end loop; if Nkind (N) = N_Function_Call then Get_First_Interp (Nam, X, It); while Present (It.Nam) loop if Ekind (It.Nam) = E_Function or else Ekind (It.Nam) = E_Operator then return; else Get_Next_Interp (X, It); end if; end loop; -- If all interpretations are procedures, this deserves a -- more precise message. Ditto if this appears as the prefix -- of a selected component, which may be a lexical error. Error_Msg_N ("\context requires function call, found procedure name", Nam); if Nkind (Parent (N)) = N_Selected_Component and then N = Prefix (Parent (N)) then Error_Msg_N -- CODEFIX ("\period should probably be semicolon", Parent (N)); end if; elsif Nkind (N) = N_Procedure_Call_Statement and then not Void_Interp_Seen then Error_Msg_N ( "\function name found in procedure call", Nam); end if; All_Errors_Mode := Err_Mode; end Diagnose_Call; --------------------------- -- Find_Arithmetic_Types -- --------------------------- procedure Find_Arithmetic_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id) is Index1 : Interp_Index; Index2 : Interp_Index; It1 : Interp; It2 : Interp; procedure Check_Right_Argument (T : Entity_Id); -- Check right operand of operator -------------------------- -- Check_Right_Argument -- -------------------------- procedure Check_Right_Argument (T : Entity_Id) is begin if not Is_Overloaded (R) then Check_Arithmetic_Pair (T, Etype (R), Op_Id, N); else Get_First_Interp (R, Index2, It2); while Present (It2.Typ) loop Check_Arithmetic_Pair (T, It2.Typ, Op_Id, N); Get_Next_Interp (Index2, It2); end loop; end if; end Check_Right_Argument; -- Start of processing for Find_Arithmetic_Types begin if not Is_Overloaded (L) then Check_Right_Argument (Etype (L)); else Get_First_Interp (L, Index1, It1); while Present (It1.Typ) loop Check_Right_Argument (It1.Typ); Get_Next_Interp (Index1, It1); end loop; end if; end Find_Arithmetic_Types; ------------------------ -- Find_Boolean_Types -- ------------------------ procedure Find_Boolean_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id) is Index : Interp_Index; It : Interp; procedure Check_Numeric_Argument (T : Entity_Id); -- Special case for logical operations one of whose operands is an -- integer literal. If both are literal the result is any modular type. ---------------------------- -- Check_Numeric_Argument -- ---------------------------- procedure Check_Numeric_Argument (T : Entity_Id) is begin if T = Universal_Integer then Add_One_Interp (N, Op_Id, Any_Modular); elsif Is_Modular_Integer_Type (T) then Add_One_Interp (N, Op_Id, T); end if; end Check_Numeric_Argument; -- Start of processing for Find_Boolean_Types begin if not Is_Overloaded (L) then if Etype (L) = Universal_Integer or else Etype (L) = Any_Modular then if not Is_Overloaded (R) then Check_Numeric_Argument (Etype (R)); else Get_First_Interp (R, Index, It); while Present (It.Typ) loop Check_Numeric_Argument (It.Typ); Get_Next_Interp (Index, It); end loop; end if; -- If operands are aggregates, we must assume that they may be -- boolean arrays, and leave disambiguation for the second pass. -- If only one is an aggregate, verify that the other one has an -- interpretation as a boolean array elsif Nkind (L) = N_Aggregate then if Nkind (R) = N_Aggregate then Add_One_Interp (N, Op_Id, Etype (L)); elsif not Is_Overloaded (R) then if Valid_Boolean_Arg (Etype (R)) then Add_One_Interp (N, Op_Id, Etype (R)); end if; else Get_First_Interp (R, Index, It); while Present (It.Typ) loop if Valid_Boolean_Arg (It.Typ) then Add_One_Interp (N, Op_Id, It.Typ); end if; Get_Next_Interp (Index, It); end loop; end if; elsif Valid_Boolean_Arg (Etype (L)) and then Has_Compatible_Type (R, Etype (L)) then Add_One_Interp (N, Op_Id, Etype (L)); end if; else Get_First_Interp (L, Index, It); while Present (It.Typ) loop if Valid_Boolean_Arg (It.Typ) and then Has_Compatible_Type (R, It.Typ) then Add_One_Interp (N, Op_Id, It.Typ); end if; Get_Next_Interp (Index, It); end loop; end if; end Find_Boolean_Types; --------------------------- -- Find_Comparison_Types -- --------------------------- procedure Find_Comparison_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id) is Index : Interp_Index; It : Interp; Found : Boolean := False; I_F : Interp_Index; T_F : Entity_Id; Scop : Entity_Id := Empty; procedure Try_One_Interp (T1 : Entity_Id); -- Routine to try one proposed interpretation. Note that the context -- of the operator plays no role in resolving the arguments, so that -- if there is more than one interpretation of the operands that is -- compatible with comparison, the operation is ambiguous. -------------------- -- Try_One_Interp -- -------------------- procedure Try_One_Interp (T1 : Entity_Id) is begin -- If the operator is an expanded name, then the type of the operand -- must be defined in the corresponding scope. If the type is -- universal, the context will impose the correct type. if Present (Scop) and then not Defined_In_Scope (T1, Scop) and then T1 /= Universal_Integer and then T1 /= Universal_Real and then T1 /= Any_String and then T1 /= Any_Composite then return; end if; if Valid_Comparison_Arg (T1) and then Has_Compatible_Type (R, T1) then if Found and then Base_Type (T1) /= Base_Type (T_F) then It := Disambiguate (L, I_F, Index, Any_Type); if It = No_Interp then Ambiguous_Operands (N); Set_Etype (L, Any_Type); return; else T_F := It.Typ; end if; else Found := True; T_F := T1; I_F := Index; end if; Set_Etype (L, T_F); Find_Non_Universal_Interpretations (N, R, Op_Id, T1); end if; end Try_One_Interp; -- Start of processing for Find_Comparison_Types begin -- If left operand is aggregate, the right operand has to -- provide a usable type for it. if Nkind (L) = N_Aggregate and then Nkind (R) /= N_Aggregate then Find_Comparison_Types (L => R, R => L, Op_Id => Op_Id, N => N); return; end if; if Nkind (N) = N_Function_Call and then Nkind (Name (N)) = N_Expanded_Name then Scop := Entity (Prefix (Name (N))); -- The prefix may be a package renaming, and the subsequent test -- requires the original package. if Ekind (Scop) = E_Package and then Present (Renamed_Entity (Scop)) then Scop := Renamed_Entity (Scop); Set_Entity (Prefix (Name (N)), Scop); end if; end if; if not Is_Overloaded (L) then Try_One_Interp (Etype (L)); else Get_First_Interp (L, Index, It); while Present (It.Typ) loop Try_One_Interp (It.Typ); Get_Next_Interp (Index, It); end loop; end if; end Find_Comparison_Types; ---------------------------------------- -- Find_Non_Universal_Interpretations -- ---------------------------------------- procedure Find_Non_Universal_Interpretations (N : Node_Id; R : Node_Id; Op_Id : Entity_Id; T1 : Entity_Id) is Index : Interp_Index; It : Interp; begin if T1 = Universal_Integer or else T1 = Universal_Real then if not Is_Overloaded (R) then Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (Etype (R))); else Get_First_Interp (R, Index, It); while Present (It.Typ) loop if Covers (It.Typ, T1) then Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (It.Typ)); end if; Get_Next_Interp (Index, It); end loop; end if; else Add_One_Interp (N, Op_Id, Standard_Boolean, Base_Type (T1)); end if; end Find_Non_Universal_Interpretations; ------------------------------ -- Find_Concatenation_Types -- ------------------------------ procedure Find_Concatenation_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id) is Op_Type : constant Entity_Id := Etype (Op_Id); begin if Is_Array_Type (Op_Type) and then not Is_Limited_Type (Op_Type) and then (Has_Compatible_Type (L, Op_Type) or else Has_Compatible_Type (L, Component_Type (Op_Type))) and then (Has_Compatible_Type (R, Op_Type) or else Has_Compatible_Type (R, Component_Type (Op_Type))) then Add_One_Interp (N, Op_Id, Op_Type); end if; end Find_Concatenation_Types; ------------------------- -- Find_Equality_Types -- ------------------------- procedure Find_Equality_Types (L, R : Node_Id; Op_Id : Entity_Id; N : Node_Id) is Index : Interp_Index; It : Interp; Found : Boolean := False; I_F : Interp_Index; T_F : Entity_Id; Scop : Entity_Id := Empty; procedure Try_One_Interp (T1 : Entity_Id); -- The context of the equality operator plays no role in resolving the -- arguments, so that if there is more than one interpretation of the -- operands that is compatible with equality, the construct is ambiguous -- and an error can be emitted now, after trying to disambiguate, i.e. -- applying preference rules. -------------------- -- Try_One_Interp -- -------------------- procedure Try_One_Interp (T1 : Entity_Id) is Bas : constant Entity_Id := Base_Type (T1); begin -- If the operator is an expanded name, then the type of the operand -- must be defined in the corresponding scope. If the type is -- universal, the context will impose the correct type. An anonymous -- type for a 'Access reference is also universal in this sense, as -- the actual type is obtained from context. -- In Ada 2005, the equality operator for anonymous access types -- is declared in Standard, and preference rules apply to it. if Present (Scop) then if Defined_In_Scope (T1, Scop) or else T1 = Universal_Integer or else T1 = Universal_Real or else T1 = Any_Access or else T1 = Any_String or else T1 = Any_Composite or else (Ekind (T1) = E_Access_Subprogram_Type and then not Comes_From_Source (T1)) then null; elsif Ekind (T1) = E_Anonymous_Access_Type and then Scop = Standard_Standard then null; else -- The scope does not contain an operator for the type return; end if; -- If we have infix notation, the operator must be usable. -- Within an instance, if the type is already established we -- know it is correct. -- In Ada 2005, the equality on anonymous access types is declared -- in Standard, and is always visible. elsif In_Open_Scopes (Scope (Bas)) or else Is_Potentially_Use_Visible (Bas) or else In_Use (Bas) or else (In_Use (Scope (Bas)) and then not Is_Hidden (Bas)) or else (In_Instance and then First_Subtype (T1) = First_Subtype (Etype (R))) or else Ekind (T1) = E_Anonymous_Access_Type then null; else -- Save candidate type for subsquent error message, if any if not Is_Limited_Type (T1) then Candidate_Type := T1; end if; return; end if; -- Ada 2005 (AI-230): Keep restriction imposed by Ada 83 and 95: -- Do not allow anonymous access types in equality operators. if Ada_Version < Ada_05 and then Ekind (T1) = E_Anonymous_Access_Type then return; end if; if T1 /= Standard_Void_Type and then not Is_Limited_Type (T1) and then not Is_Limited_Composite (T1) and then Has_Compatible_Type (R, T1) then if Found and then Base_Type (T1) /= Base_Type (T_F) then It := Disambiguate (L, I_F, Index, Any_Type); if It = No_Interp then Ambiguous_Operands (N); Set_Etype (L, Any_Type); return; else T_F := It.Typ; end if; else Found := True; T_F := T1; I_F := Index; end if; if not Analyzed (L) then Set_Etype (L, T_F); end if; Find_Non_Universal_Interpretations (N, R, Op_Id, T1); -- Case of operator was not visible, Etype still set to Any_Type if Etype (N) = Any_Type then Found := False; end if; elsif Scop = Standard_Standard and then Ekind (T1) = E_Anonymous_Access_Type then Found := True; end if; end Try_One_Interp; -- Start of processing for Find_Equality_Types begin -- If left operand is aggregate, the right operand has to -- provide a usable type for it. if Nkind (L) = N_Aggregate and then Nkind (R) /= N_Aggregate then Find_Equality_Types (L => R, R => L, Op_Id => Op_Id, N => N); return; end if; if Nkind (N) = N_Function_Call and then Nkind (Name (N)) = N_Expanded_Name then Scop := Entity (Prefix (Name (N))); -- The prefix may be a package renaming, and the subsequent test -- requires the original package. if Ekind (Scop) = E_Package and then Present (Renamed_Entity (Scop)) then Scop := Renamed_Entity (Scop); Set_Entity (Prefix (Name (N)), Scop); end if; end if; if not Is_Overloaded (L) then Try_One_Interp (Etype (L)); else Get_First_Interp (L, Index, It); while Present (It.Typ) loop Try_One_Interp (It.Typ); Get_Next_Interp (Index, It); end loop; end if; end Find_Equality_Types; ------------------------- -- Find_Negation_Types -- ------------------------- procedure Find_Negation_Types (R : Node_Id; Op_Id : Entity_Id; N : Node_Id) is Index : Interp_Index; It : Interp; begin if not Is_Overloaded (R) then if Etype (R) = Universal_Integer then Add_One_Interp (N, Op_Id, Any_Modular); elsif Valid_Boolean_Arg (Etype (R)) then Add_One_Interp (N, Op_Id, Etype (R)); end if; else Get_First_Interp (R, Index, It); while Present (It.Typ) loop if Valid_Boolean_Arg (It.Typ) then Add_One_Interp (N, Op_Id, It.Typ); end if; Get_Next_Interp (Index, It); end loop; end if; end Find_Negation_Types; ------------------------------ -- Find_Primitive_Operation -- ------------------------------ function Find_Primitive_Operation (N : Node_Id) return Boolean is Obj : constant Node_Id := Prefix (N); Op : constant Node_Id := Selector_Name (N); Prim : Elmt_Id; Prims : Elist_Id; Typ : Entity_Id; begin Set_Etype (Op, Any_Type); if Is_Access_Type (Etype (Obj)) then Typ := Designated_Type (Etype (Obj)); else Typ := Etype (Obj); end if; if Is_Class_Wide_Type (Typ) then Typ := Root_Type (Typ); end if; Prims := Primitive_Operations (Typ); Prim := First_Elmt (Prims); while Present (Prim) loop if Chars (Node (Prim)) = Chars (Op) then Add_One_Interp (Op, Node (Prim), Etype (Node (Prim))); Set_Etype (N, Etype (Node (Prim))); end if; Next_Elmt (Prim); end loop; -- Now look for class-wide operations of the type or any of its -- ancestors by iterating over the homonyms of the selector. declare Cls_Type : constant Entity_Id := Class_Wide_Type (Typ); Hom : Entity_Id; begin Hom := Current_Entity (Op); while Present (Hom) loop if (Ekind (Hom) = E_Procedure or else Ekind (Hom) = E_Function) and then Scope (Hom) = Scope (Typ) and then Present (First_Formal (Hom)) and then (Base_Type (Etype (First_Formal (Hom))) = Cls_Type or else (Is_Access_Type (Etype (First_Formal (Hom))) and then Ekind (Etype (First_Formal (Hom))) = E_Anonymous_Access_Type and then Base_Type (Designated_Type (Etype (First_Formal (Hom)))) = Cls_Type)) then Add_One_Interp (Op, Hom, Etype (Hom)); Set_Etype (N, Etype (Hom)); end if; Hom := Homonym (Hom); end loop; end; return Etype (Op) /= Any_Type; end Find_Primitive_Operation; ---------------------- -- Find_Unary_Types -- ---------------------- procedure Find_Unary_Types (R : Node_Id; Op_Id : Entity_Id; N : Node_Id) is Index : Interp_Index; It : Interp; begin if not Is_Overloaded (R) then if Is_Numeric_Type (Etype (R)) then Add_One_Interp (N, Op_Id, Base_Type (Etype (R))); end if; else Get_First_Interp (R, Index, It); while Present (It.Typ) loop if Is_Numeric_Type (It.Typ) then Add_One_Interp (N, Op_Id, Base_Type (It.Typ)); end if; Get_Next_Interp (Index, It); end loop; end if; end Find_Unary_Types; ------------------ -- Junk_Operand -- ------------------ function Junk_Operand (N : Node_Id) return Boolean is Enode : Node_Id; begin if Error_Posted (N) then return False; end if; -- Get entity to be tested if Is_Entity_Name (N) and then Present (Entity (N)) then Enode := N; -- An odd case, a procedure name gets converted to a very peculiar -- function call, and here is where we detect this happening. elsif Nkind (N) = N_Function_Call and then Is_Entity_Name (Name (N)) and then Present (Entity (Name (N))) then Enode := Name (N); -- Another odd case, there are at least some cases of selected -- components where the selected component is not marked as having -- an entity, even though the selector does have an entity elsif Nkind (N) = N_Selected_Component and then Present (Entity (Selector_Name (N))) then Enode := Selector_Name (N); else return False; end if; -- Now test the entity we got to see if it is a bad case case Ekind (Entity (Enode)) is when E_Package => Error_Msg_N ("package name cannot be used as operand", Enode); when Generic_Unit_Kind => Error_Msg_N ("generic unit name cannot be used as operand", Enode); when Type_Kind => Error_Msg_N ("subtype name cannot be used as operand", Enode); when Entry_Kind => Error_Msg_N ("entry name cannot be used as operand", Enode); when E_Procedure => Error_Msg_N ("procedure name cannot be used as operand", Enode); when E_Exception => Error_Msg_N ("exception name cannot be used as operand", Enode); when E_Block | E_Label | E_Loop => Error_Msg_N ("label name cannot be used as operand", Enode); when others => return False; end case; return True; end Junk_Operand; -------------------- -- Operator_Check -- -------------------- procedure Operator_Check (N : Node_Id) is begin Remove_Abstract_Operations (N); -- Test for case of no interpretation found for operator if Etype (N) = Any_Type then declare L : Node_Id; R : Node_Id; Op_Id : Entity_Id := Empty; begin R := Right_Opnd (N); if Nkind (N) in N_Binary_Op then L := Left_Opnd (N); else L := Empty; end if; -- If either operand has no type, then don't complain further, -- since this simply means that we have a propagated error. if R = Error or else Etype (R) = Any_Type or else (Nkind (N) in N_Binary_Op and then Etype (L) = Any_Type) then return; -- We explicitly check for the case of concatenation of component -- with component to avoid reporting spurious matching array types -- that might happen to be lurking in distant packages (such as -- run-time packages). This also prevents inconsistencies in the -- messages for certain ACVC B tests, which can vary depending on -- types declared in run-time interfaces. Another improvement when -- aggregates are present is to look for a well-typed operand. elsif Present (Candidate_Type) and then (Nkind (N) /= N_Op_Concat or else Is_Array_Type (Etype (L)) or else Is_Array_Type (Etype (R))) then if Nkind (N) = N_Op_Concat then if Etype (L) /= Any_Composite and then Is_Array_Type (Etype (L)) then Candidate_Type := Etype (L); elsif Etype (R) /= Any_Composite and then Is_Array_Type (Etype (R)) then Candidate_Type := Etype (R); end if; end if; Error_Msg_NE ("operator for} is not directly visible!", N, First_Subtype (Candidate_Type)); Error_Msg_N ("use clause would make operation legal!", N); return; -- If either operand is a junk operand (e.g. package name), then -- post appropriate error messages, but do not complain further. -- Note that the use of OR in this test instead of OR ELSE is -- quite deliberate, we may as well check both operands in the -- binary operator case. elsif Junk_Operand (R) or (Nkind (N) in N_Binary_Op and then Junk_Operand (L)) then return; -- If we have a logical operator, one of whose operands is -- Boolean, then we know that the other operand cannot resolve to -- Boolean (since we got no interpretations), but in that case we -- pretty much know that the other operand should be Boolean, so -- resolve it that way (generating an error) elsif Nkind_In (N, N_Op_And, N_Op_Or, N_Op_Xor) then if Etype (L) = Standard_Boolean then Resolve (R, Standard_Boolean); return; elsif Etype (R) = Standard_Boolean then Resolve (L, Standard_Boolean); return; end if; -- For an arithmetic operator or comparison operator, if one -- of the operands is numeric, then we know the other operand -- is not the same numeric type. If it is a non-numeric type, -- then probably it is intended to match the other operand. elsif Nkind_In (N, N_Op_Add, N_Op_Divide, N_Op_Ge, N_Op_Gt, N_Op_Le) or else Nkind_In (N, N_Op_Lt, N_Op_Mod, N_Op_Multiply, N_Op_Rem, N_Op_Subtract) then if Is_Numeric_Type (Etype (L)) and then not Is_Numeric_Type (Etype (R)) then Resolve (R, Etype (L)); return; elsif Is_Numeric_Type (Etype (R)) and then not Is_Numeric_Type (Etype (L)) then Resolve (L, Etype (R)); return; end if; -- Comparisons on A'Access are common enough to deserve a -- special message. elsif Nkind_In (N, N_Op_Eq, N_Op_Ne) and then Ekind (Etype (L)) = E_Access_Attribute_Type and then Ekind (Etype (R)) = E_Access_Attribute_Type then Error_Msg_N ("two access attributes cannot be compared directly", N); Error_Msg_N ("\use qualified expression for one of the operands", N); return; -- Another one for C programmers elsif Nkind (N) = N_Op_Concat and then Valid_Boolean_Arg (Etype (L)) and then Valid_Boolean_Arg (Etype (R)) then Error_Msg_N ("invalid operands for concatenation", N); Error_Msg_N -- CODEFIX ("\maybe AND was meant", N); return; -- A special case for comparison of access parameter with null elsif Nkind (N) = N_Op_Eq and then Is_Entity_Name (L) and then Nkind (Parent (Entity (L))) = N_Parameter_Specification and then Nkind (Parameter_Type (Parent (Entity (L)))) = N_Access_Definition and then Nkind (R) = N_Null then Error_Msg_N ("access parameter is not allowed to be null", L); Error_Msg_N ("\(call would raise Constraint_Error)", L); return; -- Another special case for exponentiation, where the right -- operand must be Natural, independently of the base. elsif Nkind (N) = N_Op_Expon and then Is_Numeric_Type (Etype (L)) and then not Is_Overloaded (R) and then First_Subtype (Base_Type (Etype (R))) /= Standard_Integer and then Base_Type (Etype (R)) /= Universal_Integer then Error_Msg_NE ("exponent must be of type Natural, found}", R, Etype (R)); return; end if; -- If we fall through then just give general message. Note that in -- the following messages, if the operand is overloaded we choose -- an arbitrary type to complain about, but that is probably more -- useful than not giving a type at all. if Nkind (N) in N_Unary_Op then Error_Msg_Node_2 := Etype (R); Error_Msg_N ("operator& not defined for}", N); return; else if Nkind (N) in N_Binary_Op then if not Is_Overloaded (L) and then not Is_Overloaded (R) and then Base_Type (Etype (L)) = Base_Type (Etype (R)) then Error_Msg_Node_2 := First_Subtype (Etype (R)); Error_Msg_N ("there is no applicable operator& for}", N); else -- Another attempt to find a fix: one of the candidate -- interpretations may not be use-visible. This has -- already been checked for predefined operators, so -- we examine only user-defined functions. Op_Id := Get_Name_Entity_Id (Chars (N)); while Present (Op_Id) loop if Ekind (Op_Id) /= E_Operator and then Is_Overloadable (Op_Id) then if not Is_Immediately_Visible (Op_Id) and then not In_Use (Scope (Op_Id)) and then not Is_Abstract_Subprogram (Op_Id) and then not Is_Hidden (Op_Id) and then Ekind (Scope (Op_Id)) = E_Package and then Has_Compatible_Type (L, Etype (First_Formal (Op_Id))) and then Present (Next_Formal (First_Formal (Op_Id))) and then Has_Compatible_Type (R, Etype (Next_Formal (First_Formal (Op_Id)))) then Error_Msg_N ("No legal interpretation for operator&", N); Error_Msg_NE ("\use clause on& would make operation legal", N, Scope (Op_Id)); exit; end if; end if; Op_Id := Homonym (Op_Id); end loop; if No (Op_Id) then Error_Msg_N ("invalid operand types for operator&", N); if Nkind (N) /= N_Op_Concat then Error_Msg_NE ("\left operand has}!", N, Etype (L)); Error_Msg_NE ("\right operand has}!", N, Etype (R)); end if; end if; end if; end if; end if; end; end if; end Operator_Check; ----------------------------------------- -- Process_Implicit_Dereference_Prefix -- ----------------------------------------- function Process_Implicit_Dereference_Prefix (E : Entity_Id; P : Entity_Id) return Entity_Id is Ref : Node_Id; Typ : constant Entity_Id := Designated_Type (Etype (P)); begin if Present (E) and then (Operating_Mode = Check_Semantics or else not Expander_Active) then -- We create a dummy reference to E to ensure that the reference -- is not considered as part of an assignment (an implicit -- dereference can never assign to its prefix). The Comes_From_Source -- attribute needs to be propagated for accurate warnings. Ref := New_Reference_To (E, Sloc (P)); Set_Comes_From_Source (Ref, Comes_From_Source (P)); Generate_Reference (E, Ref); end if; -- An implicit dereference is a legal occurrence of an -- incomplete type imported through a limited_with clause, -- if the full view is visible. if From_With_Type (Typ) and then not From_With_Type (Scope (Typ)) and then (Is_Immediately_Visible (Scope (Typ)) or else (Is_Child_Unit (Scope (Typ)) and then Is_Visible_Child_Unit (Scope (Typ)))) then return Available_View (Typ); else return Typ; end if; end Process_Implicit_Dereference_Prefix; -------------------------------- -- Remove_Abstract_Operations -- -------------------------------- procedure Remove_Abstract_Operations (N : Node_Id) is Abstract_Op : Entity_Id := Empty; Address_Kludge : Boolean := False; I : Interp_Index; It : Interp; -- AI-310: If overloaded, remove abstract non-dispatching operations. We -- activate this if either extensions are enabled, or if the abstract -- operation in question comes from a predefined file. This latter test -- allows us to use abstract to make operations invisible to users. In -- particular, if type Address is non-private and abstract subprograms -- are used to hide its operators, they will be truly hidden. type Operand_Position is (First_Op, Second_Op); Univ_Type : constant Entity_Id := Universal_Interpretation (N); procedure Remove_Address_Interpretations (Op : Operand_Position); -- Ambiguities may arise when the operands are literal and the address -- operations in s-auxdec are visible. In that case, remove the -- interpretation of a literal as Address, to retain the semantics of -- Address as a private type. ------------------------------------ -- Remove_Address_Interpretations -- ------------------------------------ procedure Remove_Address_Interpretations (Op : Operand_Position) is Formal : Entity_Id; begin if Is_Overloaded (N) then Get_First_Interp (N, I, It); while Present (It.Nam) loop Formal := First_Entity (It.Nam); if Op = Second_Op then Formal := Next_Entity (Formal); end if; if Is_Descendent_Of_Address (Etype (Formal)) then Address_Kludge := True; Remove_Interp (I); end if; Get_Next_Interp (I, It); end loop; end if; end Remove_Address_Interpretations; -- Start of processing for Remove_Abstract_Operations begin if Is_Overloaded (N) then Get_First_Interp (N, I, It); while Present (It.Nam) loop if Is_Overloadable (It.Nam) and then Is_Abstract_Subprogram (It.Nam) and then not Is_Dispatching_Operation (It.Nam) then Abstract_Op := It.Nam; if Is_Descendent_Of_Address (It.Typ) then Address_Kludge := True; Remove_Interp (I); exit; -- In Ada 2005, this operation does not participate in Overload -- resolution. If the operation is defined in a predefined -- unit, it is one of the operations declared abstract in some -- variants of System, and it must be removed as well. elsif Ada_Version >= Ada_05 or else Is_Predefined_File_Name (Unit_File_Name (Get_Source_Unit (It.Nam))) then Remove_Interp (I); exit; end if; end if; Get_Next_Interp (I, It); end loop; if No (Abstract_Op) then -- If some interpretation yields an integer type, it is still -- possible that there are address interpretations. Remove them -- if one operand is a literal, to avoid spurious ambiguities -- on systems where Address is a visible integer type. if Is_Overloaded (N) and then Nkind (N) in N_Op and then Is_Integer_Type (Etype (N)) then if Nkind (N) in N_Binary_Op then if Nkind (Right_Opnd (N)) = N_Integer_Literal then Remove_Address_Interpretations (Second_Op); elsif Nkind (Right_Opnd (N)) = N_Integer_Literal then Remove_Address_Interpretations (First_Op); end if; end if; end if; elsif Nkind (N) in N_Op then -- Remove interpretations that treat literals as addresses. This -- is never appropriate, even when Address is defined as a visible -- Integer type. The reason is that we would really prefer Address -- to behave as a private type, even in this case, which is there -- only to accommodate oddities of VMS address sizes. If Address -- is a visible integer type, we get lots of overload ambiguities. if Nkind (N) in N_Binary_Op then declare U1 : constant Boolean := Present (Universal_Interpretation (Right_Opnd (N))); U2 : constant Boolean := Present (Universal_Interpretation (Left_Opnd (N))); begin if U1 then Remove_Address_Interpretations (Second_Op); end if; if U2 then Remove_Address_Interpretations (First_Op); end if; if not (U1 and U2) then -- Remove corresponding predefined operator, which is -- always added to the overload set. Get_First_Interp (N, I, It); while Present (It.Nam) loop if Scope (It.Nam) = Standard_Standard and then Base_Type (It.Typ) = Base_Type (Etype (Abstract_Op)) then Remove_Interp (I); end if; Get_Next_Interp (I, It); end loop; elsif Is_Overloaded (N) and then Present (Univ_Type) then -- If both operands have a universal interpretation, -- it is still necessary to remove interpretations that -- yield Address. Any remaining ambiguities will be -- removed in Disambiguate. Get_First_Interp (N, I, It); while Present (It.Nam) loop if Is_Descendent_Of_Address (It.Typ) then Remove_Interp (I); elsif not Is_Type (It.Nam) then Set_Entity (N, It.Nam); end if; Get_Next_Interp (I, It); end loop; end if; end; end if; elsif Nkind (N) = N_Function_Call and then (Nkind (Name (N)) = N_Operator_Symbol or else (Nkind (Name (N)) = N_Expanded_Name and then Nkind (Selector_Name (Name (N))) = N_Operator_Symbol)) then declare Arg1 : constant Node_Id := First (Parameter_Associations (N)); U1 : constant Boolean := Present (Universal_Interpretation (Arg1)); U2 : constant Boolean := Present (Next (Arg1)) and then Present (Universal_Interpretation (Next (Arg1))); begin if U1 then Remove_Address_Interpretations (First_Op); end if; if U2 then Remove_Address_Interpretations (Second_Op); end if; if not (U1 and U2) then Get_First_Interp (N, I, It); while Present (It.Nam) loop if Scope (It.Nam) = Standard_Standard and then It.Typ = Base_Type (Etype (Abstract_Op)) then Remove_Interp (I); end if; Get_Next_Interp (I, It); end loop; end if; end; end if; -- If the removal has left no valid interpretations, emit an error -- message now and label node as illegal. if Present (Abstract_Op) then Get_First_Interp (N, I, It); if No (It.Nam) then -- Removal of abstract operation left no viable candidate Set_Etype (N, Any_Type); Error_Msg_Sloc := Sloc (Abstract_Op); Error_Msg_NE ("cannot call abstract operation& declared#", N, Abstract_Op); -- In Ada 2005, an abstract operation may disable predefined -- operators. Since the context is not yet known, we mark the -- predefined operators as potentially hidden. Do not include -- predefined operators when addresses are involved since this -- case is handled separately. elsif Ada_Version >= Ada_05 and then not Address_Kludge then while Present (It.Nam) loop if Is_Numeric_Type (It.Typ) and then Scope (It.Typ) = Standard_Standard then Set_Abstract_Op (I, Abstract_Op); end if; Get_Next_Interp (I, It); end loop; end if; end if; end if; end Remove_Abstract_Operations; ----------------------- -- Try_Indirect_Call -- ----------------------- function Try_Indirect_Call (N : Node_Id; Nam : Entity_Id; Typ : Entity_Id) return Boolean is Actual : Node_Id; Formal : Entity_Id; Call_OK : Boolean; pragma Warnings (Off, Call_OK); begin Normalize_Actuals (N, Designated_Type (Typ), False, Call_OK); Actual := First_Actual (N); Formal := First_Formal (Designated_Type (Typ)); while Present (Actual) and then Present (Formal) loop if not Has_Compatible_Type (Actual, Etype (Formal)) then return False; end if; Next (Actual); Next_Formal (Formal); end loop; if No (Actual) and then No (Formal) then Add_One_Interp (N, Nam, Etype (Designated_Type (Typ))); -- Nam is a candidate interpretation for the name in the call, -- if it is not an indirect call. if not Is_Type (Nam) and then Is_Entity_Name (Name (N)) then Set_Entity (Name (N), Nam); end if; return True; else return False; end if; end Try_Indirect_Call; ---------------------- -- Try_Indexed_Call -- ---------------------- function Try_Indexed_Call (N : Node_Id; Nam : Entity_Id; Typ : Entity_Id; Skip_First : Boolean) return Boolean is Loc : constant Source_Ptr := Sloc (N); Actuals : constant List_Id := Parameter_Associations (N); Actual : Node_Id; Index : Entity_Id; begin Actual := First (Actuals); -- If the call was originally written in prefix form, skip the first -- actual, which is obviously not defaulted. if Skip_First then Next (Actual); end if; Index := First_Index (Typ); while Present (Actual) and then Present (Index) loop -- If the parameter list has a named association, the expression -- is definitely a call and not an indexed component. if Nkind (Actual) = N_Parameter_Association then return False; end if; if Is_Entity_Name (Actual) and then Is_Type (Entity (Actual)) and then No (Next (Actual)) then Rewrite (N, Make_Slice (Loc, Prefix => Make_Function_Call (Loc, Name => Relocate_Node (Name (N))), Discrete_Range => New_Occurrence_Of (Entity (Actual), Sloc (Actual)))); Analyze (N); return True; elsif not Has_Compatible_Type (Actual, Etype (Index)) then return False; end if; Next (Actual); Next_Index (Index); end loop; if No (Actual) and then No (Index) then Add_One_Interp (N, Nam, Component_Type (Typ)); -- Nam is a candidate interpretation for the name in the call, -- if it is not an indirect call. if not Is_Type (Nam) and then Is_Entity_Name (Name (N)) then Set_Entity (Name (N), Nam); end if; return True; else return False; end if; end Try_Indexed_Call; -------------------------- -- Try_Object_Operation -- -------------------------- function Try_Object_Operation (N : Node_Id) return Boolean is K : constant Node_Kind := Nkind (Parent (N)); Is_Subprg_Call : constant Boolean := Nkind_In (K, N_Procedure_Call_Statement, N_Function_Call); Loc : constant Source_Ptr := Sloc (N); Obj : constant Node_Id := Prefix (N); Subprog : constant Node_Id := Make_Identifier (Sloc (Selector_Name (N)), Chars => Chars (Selector_Name (N))); -- Identifier on which possible interpretations will be collected Report_Error : Boolean := False; -- If no candidate interpretation matches the context, redo the -- analysis with error enabled to provide additional information. Actual : Node_Id; Candidate : Entity_Id := Empty; New_Call_Node : Node_Id := Empty; Node_To_Replace : Node_Id; Obj_Type : Entity_Id := Etype (Obj); Success : Boolean := False; function Valid_Candidate (Success : Boolean; Call : Node_Id; Subp : Entity_Id) return Entity_Id; -- If the subprogram is a valid interpretation, record it, and add -- to the list of interpretations of Subprog. procedure Complete_Object_Operation (Call_Node : Node_Id; Node_To_Replace : Node_Id); -- Make Subprog the name of Call_Node, replace Node_To_Replace with -- Call_Node, insert the object (or its dereference) as the first actual -- in the call, and complete the analysis of the call. procedure Report_Ambiguity (Op : Entity_Id); -- If a prefixed procedure call is ambiguous, indicate whether the -- call includes an implicit dereference or an implicit 'Access. procedure Transform_Object_Operation (Call_Node : out Node_Id; Node_To_Replace : out Node_Id); -- Transform Obj.Operation (X, Y,,) into Operation (Obj, X, Y ..) -- Call_Node is the resulting subprogram call, Node_To_Replace is -- either N or the parent of N, and Subprog is a reference to the -- subprogram we are trying to match. function Try_Class_Wide_Operation (Call_Node : Node_Id; Node_To_Replace : Node_Id) return Boolean; -- Traverse all ancestor types looking for a class-wide subprogram -- for which the current operation is a valid non-dispatching call. procedure Try_One_Prefix_Interpretation (T : Entity_Id); -- If prefix is overloaded, its interpretation may include different -- tagged types, and we must examine the primitive operations and -- the class-wide operations of each in order to find candidate -- interpretations for the call as a whole. function Try_Primitive_Operation (Call_Node : Node_Id; Node_To_Replace : Node_Id) return Boolean; -- Traverse the list of primitive subprograms looking for a dispatching -- operation for which the current node is a valid call . --------------------- -- Valid_Candidate -- --------------------- function Valid_Candidate (Success : Boolean; Call : Node_Id; Subp : Entity_Id) return Entity_Id is Arr_Type : Entity_Id; Comp_Type : Entity_Id; begin -- If the subprogram is a valid interpretation, record it in global -- variable Subprog, to collect all possible overloadings. if Success then if Subp /= Entity (Subprog) then Add_One_Interp (Subprog, Subp, Etype (Subp)); end if; end if; -- If the call may be an indexed call, retrieve component type of -- resulting expression, and add possible interpretation. Arr_Type := Empty; Comp_Type := Empty; if Nkind (Call) = N_Function_Call and then Nkind (Parent (N)) = N_Indexed_Component and then Needs_One_Actual (Subp) then if Is_Array_Type (Etype (Subp)) then Arr_Type := Etype (Subp); elsif Is_Access_Type (Etype (Subp)) and then Is_Array_Type (Designated_Type (Etype (Subp))) then Arr_Type := Designated_Type (Etype (Subp)); end if; end if; if Present (Arr_Type) then -- Verify that the actuals (excluding the object) -- match the types of the indices. declare Actual : Node_Id; Index : Node_Id; begin Actual := Next (First_Actual (Call)); Index := First_Index (Arr_Type); while Present (Actual) and then Present (Index) loop if not Has_Compatible_Type (Actual, Etype (Index)) then Arr_Type := Empty; exit; end if; Next_Actual (Actual); Next_Index (Index); end loop; if No (Actual) and then No (Index) and then Present (Arr_Type) then Comp_Type := Component_Type (Arr_Type); end if; end; if Present (Comp_Type) and then Etype (Subprog) /= Comp_Type then Add_One_Interp (Subprog, Subp, Comp_Type); end if; end if; if Etype (Call) /= Any_Type then return Subp; else return Empty; end if; end Valid_Candidate; ------------------------------- -- Complete_Object_Operation -- ------------------------------- procedure Complete_Object_Operation (Call_Node : Node_Id; Node_To_Replace : Node_Id) is Control : constant Entity_Id := First_Formal (Entity (Subprog)); Formal_Type : constant Entity_Id := Etype (Control); First_Actual : Node_Id; begin -- Place the name of the operation, with its interpretations, -- on the rewritten call. Set_Name (Call_Node, Subprog); First_Actual := First (Parameter_Associations (Call_Node)); -- For cross-reference purposes, treat the new node as being in -- the source if the original one is. Set_Comes_From_Source (Subprog, Comes_From_Source (N)); Set_Comes_From_Source (Call_Node, Comes_From_Source (N)); if Nkind (N) = N_Selected_Component and then not Inside_A_Generic then Set_Entity (Selector_Name (N), Entity (Subprog)); end if; -- If need be, rewrite first actual as an explicit dereference -- If the call is overloaded, the rewriting can only be done -- once the primitive operation is identified. if Is_Overloaded (Subprog) then -- The prefix itself may be overloaded, and its interpretations -- must be propagated to the new actual in the call. if Is_Overloaded (Obj) then Save_Interps (Obj, First_Actual); end if; Rewrite (First_Actual, Obj); elsif not Is_Access_Type (Formal_Type) and then Is_Access_Type (Etype (Obj)) then Rewrite (First_Actual, Make_Explicit_Dereference (Sloc (Obj), Obj)); Analyze (First_Actual); -- If we need to introduce an explicit dereference, verify that -- the resulting actual is compatible with the mode of the formal. if Ekind (First_Formal (Entity (Subprog))) /= E_In_Parameter and then Is_Access_Constant (Etype (Obj)) then Error_Msg_NE ("expect variable in call to&", Prefix (N), Entity (Subprog)); end if; -- Conversely, if the formal is an access parameter and the object -- is not, replace the actual with a 'Access reference. Its analysis -- will check that the object is aliased. elsif Is_Access_Type (Formal_Type) and then not Is_Access_Type (Etype (Obj)) then -- A special case: A.all'access is illegal if A is an access to a -- constant and the context requires an access to a variable. if not Is_Access_Constant (Formal_Type) then if (Nkind (Obj) = N_Explicit_Dereference and then Is_Access_Constant (Etype (Prefix (Obj)))) or else not Is_Variable (Obj) then Error_Msg_NE ("actual for& must be a variable", Obj, Control); end if; end if; Rewrite (First_Actual, Make_Attribute_Reference (Loc, Attribute_Name => Name_Access, Prefix => Relocate_Node (Obj))); if not Is_Aliased_View (Obj) then Error_Msg_NE ("object in prefixed call to& must be aliased" & " (RM-2005 4.3.1 (13))", Prefix (First_Actual), Subprog); end if; Analyze (First_Actual); else if Is_Overloaded (Obj) then Save_Interps (Obj, First_Actual); end if; Rewrite (First_Actual, Obj); end if; Rewrite (Node_To_Replace, Call_Node); -- Propagate the interpretations collected in subprog to the new -- function call node, to be resolved from context. if Is_Overloaded (Subprog) then Save_Interps (Subprog, Node_To_Replace); else Analyze (Node_To_Replace); end if; end Complete_Object_Operation; ---------------------- -- Report_Ambiguity -- ---------------------- procedure Report_Ambiguity (Op : Entity_Id) is Access_Formal : constant Boolean := Is_Access_Type (Etype (First_Formal (Op))); Access_Actual : constant Boolean := Is_Access_Type (Etype (Prefix (N))); begin Error_Msg_Sloc := Sloc (Op); if Access_Formal and then not Access_Actual then if Nkind (Parent (Op)) = N_Full_Type_Declaration then Error_Msg_N ("\possible interpretation" & " (inherited, with implicit 'Access) #", N); else Error_Msg_N ("\possible interpretation (with implicit 'Access) #", N); end if; elsif not Access_Formal and then Access_Actual then if Nkind (Parent (Op)) = N_Full_Type_Declaration then Error_Msg_N ("\possible interpretation" & " ( inherited, with implicit dereference) #", N); else Error_Msg_N ("\possible interpretation (with implicit dereference) #", N); end if; else if Nkind (Parent (Op)) = N_Full_Type_Declaration then Error_Msg_N ("\possible interpretation (inherited)#", N); else Error_Msg_N -- CODEFIX ("\possible interpretation#", N); end if; end if; end Report_Ambiguity; -------------------------------- -- Transform_Object_Operation -- -------------------------------- procedure Transform_Object_Operation (Call_Node : out Node_Id; Node_To_Replace : out Node_Id) is Dummy : constant Node_Id := New_Copy (Obj); -- Placeholder used as a first parameter in the call, replaced -- eventually by the proper object. Parent_Node : constant Node_Id := Parent (N); Actual : Node_Id; Actuals : List_Id; begin -- Common case covering 1) Call to a procedure and 2) Call to a -- function that has some additional actuals. if Nkind_In (Parent_Node, N_Function_Call, N_Procedure_Call_Statement) -- N is a selected component node containing the name of the -- subprogram. If N is not the name of the parent node we must -- not replace the parent node by the new construct. This case -- occurs when N is a parameterless call to a subprogram that -- is an actual parameter of a call to another subprogram. For -- example: -- Some_Subprogram (..., Obj.Operation, ...) and then Name (Parent_Node) = N then Node_To_Replace := Parent_Node; Actuals := Parameter_Associations (Parent_Node); if Present (Actuals) then Prepend (Dummy, Actuals); else Actuals := New_List (Dummy); end if; if Nkind (Parent_Node) = N_Procedure_Call_Statement then Call_Node := Make_Procedure_Call_Statement (Loc, Name => New_Copy (Subprog), Parameter_Associations => Actuals); else Call_Node := Make_Function_Call (Loc, Name => New_Copy (Subprog), Parameter_Associations => Actuals); end if; -- Before analysis, a function call appears as an indexed component -- if there are no named associations. elsif Nkind (Parent_Node) = N_Indexed_Component and then N = Prefix (Parent_Node) then Node_To_Replace := Parent_Node; Actuals := Expressions (Parent_Node); Actual := First (Actuals); while Present (Actual) loop Analyze (Actual); Next (Actual); end loop; Prepend (Dummy, Actuals); Call_Node := Make_Function_Call (Loc, Name => New_Copy (Subprog), Parameter_Associations => Actuals); -- Parameterless call: Obj.F is rewritten as F (Obj) else Node_To_Replace := N; Call_Node := Make_Function_Call (Loc, Name => New_Copy (Subprog), Parameter_Associations => New_List (Dummy)); end if; end Transform_Object_Operation; ------------------------------ -- Try_Class_Wide_Operation -- ------------------------------ function Try_Class_Wide_Operation (Call_Node : Node_Id; Node_To_Replace : Node_Id) return Boolean is Anc_Type : Entity_Id; Matching_Op : Entity_Id := Empty; Error : Boolean; procedure Traverse_Homonyms (Anc_Type : Entity_Id; Error : out Boolean); -- Traverse the homonym chain of the subprogram searching for those -- homonyms whose first formal has the Anc_Type's class-wide type, -- or an anonymous access type designating the class-wide type. If -- an ambiguity is detected, then Error is set to True. procedure Traverse_Interfaces (Anc_Type : Entity_Id; Error : out Boolean); -- Traverse the list of interfaces, if any, associated with Anc_Type -- and search for acceptable class-wide homonyms associated with each -- interface. If an ambiguity is detected, then Error is set to True. ----------------------- -- Traverse_Homonyms -- ----------------------- procedure Traverse_Homonyms (Anc_Type : Entity_Id; Error : out Boolean) is Cls_Type : Entity_Id; Hom : Entity_Id; Hom_Ref : Node_Id; Success : Boolean; begin Error := False; Cls_Type := Class_Wide_Type (Anc_Type); Hom := Current_Entity (Subprog); -- Find operation whose first parameter is of the class-wide -- type, a subtype thereof, or an anonymous access to same. while Present (Hom) loop if (Ekind (Hom) = E_Procedure or else Ekind (Hom) = E_Function) and then Scope (Hom) = Scope (Anc_Type) and then Present (First_Formal (Hom)) and then (Base_Type (Etype (First_Formal (Hom))) = Cls_Type or else (Is_Access_Type (Etype (First_Formal (Hom))) and then Ekind (Etype (First_Formal (Hom))) = E_Anonymous_Access_Type and then Base_Type (Designated_Type (Etype (First_Formal (Hom)))) = Cls_Type)) then Set_Etype (Call_Node, Any_Type); Set_Is_Overloaded (Call_Node, False); Success := False; if No (Matching_Op) then Hom_Ref := New_Reference_To (Hom, Sloc (Subprog)); Set_Etype (Call_Node, Any_Type); Set_Parent (Call_Node, Parent (Node_To_Replace)); Set_Name (Call_Node, Hom_Ref); Analyze_One_Call (N => Call_Node, Nam => Hom, Report => Report_Error, Success => Success, Skip_First => True); Matching_Op := Valid_Candidate (Success, Call_Node, Hom); else Analyze_One_Call (N => Call_Node, Nam => Hom, Report => Report_Error, Success => Success, Skip_First => True); if Present (Valid_Candidate (Success, Call_Node, Hom)) and then Nkind (Call_Node) /= N_Function_Call then Error_Msg_NE ("ambiguous call to&", N, Hom); Report_Ambiguity (Matching_Op); Report_Ambiguity (Hom); Error := True; return; end if; end if; end if; Hom := Homonym (Hom); end loop; end Traverse_Homonyms; ------------------------- -- Traverse_Interfaces -- ------------------------- procedure Traverse_Interfaces (Anc_Type : Entity_Id; Error : out Boolean) is Intface_List : constant List_Id := Abstract_Interface_List (Anc_Type); Intface : Node_Id; begin Error := False; if Is_Non_Empty_List (Intface_List) then Intface := First (Intface_List); while Present (Intface) loop -- Look for acceptable class-wide homonyms associated with -- the interface. Traverse_Homonyms (Etype (Intface), Error); if Error then return; end if; -- Continue the search by looking at each of the interface's -- associated interface ancestors. Traverse_Interfaces (Etype (Intface), Error); if Error then return; end if; Next (Intface); end loop; end if; end Traverse_Interfaces; -- Start of processing for Try_Class_Wide_Operation begin -- Loop through ancestor types (including interfaces), traversing -- the homonym chain of the subprogram, trying out those homonyms -- whose first formal has the class-wide type of the ancestor, or -- an anonymous access type designating the class-wide type. Anc_Type := Obj_Type; loop -- Look for a match among homonyms associated with the ancestor Traverse_Homonyms (Anc_Type, Error); if Error then return True; end if; -- Continue the search for matches among homonyms associated with -- any interfaces implemented by the ancestor. Traverse_Interfaces (Anc_Type, Error); if Error then return True; end if; exit when Etype (Anc_Type) = Anc_Type; Anc_Type := Etype (Anc_Type); end loop; if Present (Matching_Op) then Set_Etype (Call_Node, Etype (Matching_Op)); end if; return Present (Matching_Op); end Try_Class_Wide_Operation; ----------------------------------- -- Try_One_Prefix_Interpretation -- ----------------------------------- procedure Try_One_Prefix_Interpretation (T : Entity_Id) is begin Obj_Type := T; if Is_Access_Type (Obj_Type) then Obj_Type := Designated_Type (Obj_Type); end if; if Ekind (Obj_Type) = E_Private_Subtype then Obj_Type := Base_Type (Obj_Type); end if; if Is_Class_Wide_Type (Obj_Type) then Obj_Type := Etype (Class_Wide_Type (Obj_Type)); end if; -- The type may have be obtained through a limited_with clause, -- in which case the primitive operations are available on its -- non-limited view. If still incomplete, retrieve full view. if Ekind (Obj_Type) = E_Incomplete_Type and then From_With_Type (Obj_Type) then Obj_Type := Get_Full_View (Non_Limited_View (Obj_Type)); end if; -- If the object is not tagged, or the type is still an incomplete -- type, this is not a prefixed call. if not Is_Tagged_Type (Obj_Type) or else Is_Incomplete_Type (Obj_Type) then return; end if; if Try_Primitive_Operation (Call_Node => New_Call_Node, Node_To_Replace => Node_To_Replace) or else Try_Class_Wide_Operation (Call_Node => New_Call_Node, Node_To_Replace => Node_To_Replace) then null; end if; end Try_One_Prefix_Interpretation; ----------------------------- -- Try_Primitive_Operation -- ----------------------------- function Try_Primitive_Operation (Call_Node : Node_Id; Node_To_Replace : Node_Id) return Boolean is Elmt : Elmt_Id; Prim_Op : Entity_Id; Matching_Op : Entity_Id := Empty; Prim_Op_Ref : Node_Id := Empty; Corr_Type : Entity_Id := Empty; -- If the prefix is a synchronized type, the controlling type of -- the primitive operation is the corresponding record type, else -- this is the object type itself. Success : Boolean := False; function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id; -- For tagged types the candidate interpretations are found in -- the list of primitive operations of the type and its ancestors. -- For formal tagged types we have to find the operations declared -- in the same scope as the type (including in the generic formal -- part) because the type itself carries no primitive operations, -- except for formal derived types that inherit the operations of -- the parent and progenitors. -- If the context is a generic subprogram body, the generic formals -- are visible by name, but are not in the entity list of the -- subprogram because that list starts with the subprogram formals. -- We retrieve the candidate operations from the generic declaration. function Is_Private_Overriding (Op : Entity_Id) return Boolean; -- An operation that overrides an inherited operation in the private -- part of its package may be hidden, but if the inherited operation -- is visible a direct call to it will dispatch to the private one, -- which is therefore a valid candidate. function Valid_First_Argument_Of (Op : Entity_Id) return Boolean; -- Verify that the prefix, dereferenced if need be, is a valid -- controlling argument in a call to Op. The remaining actuals -- are checked in the subsequent call to Analyze_One_Call. ------------------------------ -- Collect_Generic_Type_Ops -- ------------------------------ function Collect_Generic_Type_Ops (T : Entity_Id) return Elist_Id is Bas : constant Entity_Id := Base_Type (T); Candidates : constant Elist_Id := New_Elmt_List; Subp : Entity_Id; Formal : Entity_Id; procedure Check_Candidate; -- The operation is a candidate if its first parameter is a -- controlling operand of the desired type. ----------------------- -- Check_Candidate; -- ----------------------- procedure Check_Candidate is begin Formal := First_Formal (Subp); if Present (Formal) and then Is_Controlling_Formal (Formal) and then (Base_Type (Etype (Formal)) = Bas or else (Is_Access_Type (Etype (Formal)) and then Designated_Type (Etype (Formal)) = Bas)) then Append_Elmt (Subp, Candidates); end if; end Check_Candidate; -- Start of processing for Collect_Generic_Type_Ops begin if Is_Derived_Type (T) then return Primitive_Operations (T); elsif Ekind (Scope (T)) = E_Procedure or else Ekind (Scope (T)) = E_Function then -- Scan the list of generic formals to find subprograms -- that may have a first controlling formal of the type. declare Decl : Node_Id; begin Decl := First (Generic_Formal_Declarations (Unit_Declaration_Node (Scope (T)))); while Present (Decl) loop if Nkind (Decl) in N_Formal_Subprogram_Declaration then Subp := Defining_Entity (Decl); Check_Candidate; end if; Next (Decl); end loop; end; return Candidates; else -- Scan the list of entities declared in the same scope as -- the type. In general this will be an open scope, given that -- the call we are analyzing can only appear within a generic -- declaration or body (either the one that declares T, or a -- child unit). Subp := First_Entity (Scope (T)); while Present (Subp) loop if Is_Overloadable (Subp) then Check_Candidate; end if; Next_Entity (Subp); end loop; return Candidates; end if; end Collect_Generic_Type_Ops; --------------------------- -- Is_Private_Overriding -- --------------------------- function Is_Private_Overriding (Op : Entity_Id) return Boolean is Visible_Op : constant Entity_Id := Homonym (Op); begin return Present (Visible_Op) and then Scope (Op) = Scope (Visible_Op) and then not Comes_From_Source (Visible_Op) and then Alias (Visible_Op) = Op and then not Is_Hidden (Visible_Op); end Is_Private_Overriding; ----------------------------- -- Valid_First_Argument_Of -- ----------------------------- function Valid_First_Argument_Of (Op : Entity_Id) return Boolean is Typ : Entity_Id := Etype (First_Formal (Op)); begin if Is_Concurrent_Type (Typ) and then Present (Corresponding_Record_Type (Typ)) then Typ := Corresponding_Record_Type (Typ); end if; -- Simple case. Object may be a subtype of the tagged type or -- may be the corresponding record of a synchronized type. return Obj_Type = Typ or else Base_Type (Obj_Type) = Typ or else Corr_Type = Typ -- Prefix can be dereferenced or else (Is_Access_Type (Corr_Type) and then Designated_Type (Corr_Type) = Typ) -- Formal is an access parameter, for which the object -- can provide an access. or else (Ekind (Typ) = E_Anonymous_Access_Type and then Designated_Type (Typ) = Base_Type (Corr_Type)); end Valid_First_Argument_Of; -- Start of processing for Try_Primitive_Operation begin -- Look for subprograms in the list of primitive operations. The name -- must be identical, and the kind of call indicates the expected -- kind of operation (function or procedure). If the type is a -- (tagged) synchronized type, the primitive ops are attached to the -- corresponding record (base) type. if Is_Concurrent_Type (Obj_Type) then if not Present (Corresponding_Record_Type (Obj_Type)) then return False; end if; Corr_Type := Base_Type (Corresponding_Record_Type (Obj_Type)); Elmt := First_Elmt (Primitive_Operations (Corr_Type)); elsif not Is_Generic_Type (Obj_Type) then Corr_Type := Obj_Type; Elmt := First_Elmt (Primitive_Operations (Obj_Type)); else Corr_Type := Obj_Type; Elmt := First_Elmt (Collect_Generic_Type_Ops (Obj_Type)); end if; while Present (Elmt) loop Prim_Op := Node (Elmt); if Chars (Prim_Op) = Chars (Subprog) and then Present (First_Formal (Prim_Op)) and then Valid_First_Argument_Of (Prim_Op) and then (Nkind (Call_Node) = N_Function_Call) = (Ekind (Prim_Op) = E_Function) then -- Ada 2005 (AI-251): If this primitive operation corresponds -- with an immediate ancestor interface there is no need to add -- it to the list of interpretations; the corresponding aliased -- primitive is also in this list of primitive operations and -- will be used instead. if (Present (Interface_Alias (Prim_Op)) and then Is_Ancestor (Find_Dispatching_Type (Alias (Prim_Op)), Corr_Type)) -- Do not consider hidden primitives unless the type is in an -- open scope or we are within an instance, where visibility -- is known to be correct, or else if this is an overriding -- operation in the private part for an inherited operation. or else (Is_Hidden (Prim_Op) and then not Is_Immediately_Visible (Obj_Type) and then not In_Instance and then not Is_Private_Overriding (Prim_Op)) then goto Continue; end if; Set_Etype (Call_Node, Any_Type); Set_Is_Overloaded (Call_Node, False); if No (Matching_Op) then Prim_Op_Ref := New_Reference_To (Prim_Op, Sloc (Subprog)); Candidate := Prim_Op; Set_Parent (Call_Node, Parent (Node_To_Replace)); Set_Name (Call_Node, Prim_Op_Ref); Success := False; Analyze_One_Call (N => Call_Node, Nam => Prim_Op, Report => Report_Error, Success => Success, Skip_First => True); Matching_Op := Valid_Candidate (Success, Call_Node, Prim_Op); -- More than one interpretation, collect for subsequent -- disambiguation. If this is a procedure call and there -- is another match, report ambiguity now. else Analyze_One_Call (N => Call_Node, Nam => Prim_Op, Report => Report_Error, Success => Success, Skip_First => True); if Present (Valid_Candidate (Success, Call_Node, Prim_Op)) and then Nkind (Call_Node) /= N_Function_Call then Error_Msg_NE ("ambiguous call to&", N, Prim_Op); Report_Ambiguity (Matching_Op); Report_Ambiguity (Prim_Op); return True; end if; end if; end if; <<Continue>> Next_Elmt (Elmt); end loop; if Present (Matching_Op) then Set_Etype (Call_Node, Etype (Matching_Op)); end if; return Present (Matching_Op); end Try_Primitive_Operation; -- Start of processing for Try_Object_Operation begin Analyze_Expression (Obj); -- Analyze the actuals if node is known to be a subprogram call if Is_Subprg_Call and then N = Name (Parent (N)) then Actual := First (Parameter_Associations (Parent (N))); while Present (Actual) loop Analyze_Expression (Actual); Next (Actual); end loop; end if; -- Build a subprogram call node, using a copy of Obj as its first -- actual. This is a placeholder, to be replaced by an explicit -- dereference when needed. Transform_Object_Operation (Call_Node => New_Call_Node, Node_To_Replace => Node_To_Replace); Set_Etype (New_Call_Node, Any_Type); Set_Etype (Subprog, Any_Type); Set_Parent (New_Call_Node, Parent (Node_To_Replace)); if not Is_Overloaded (Obj) then Try_One_Prefix_Interpretation (Obj_Type); else declare I : Interp_Index; It : Interp; begin Get_First_Interp (Obj, I, It); while Present (It.Nam) loop Try_One_Prefix_Interpretation (It.Typ); Get_Next_Interp (I, It); end loop; end; end if; if Etype (New_Call_Node) /= Any_Type then Complete_Object_Operation (Call_Node => New_Call_Node, Node_To_Replace => Node_To_Replace); return True; elsif Present (Candidate) then -- The argument list is not type correct. Re-analyze with error -- reporting enabled, and use one of the possible candidates. -- In All_Errors_Mode, re-analyze all failed interpretations. if All_Errors_Mode then Report_Error := True; if Try_Primitive_Operation (Call_Node => New_Call_Node, Node_To_Replace => Node_To_Replace) or else Try_Class_Wide_Operation (Call_Node => New_Call_Node, Node_To_Replace => Node_To_Replace) then null; end if; else Analyze_One_Call (N => New_Call_Node, Nam => Candidate, Report => True, Success => Success, Skip_First => True); end if; -- No need for further errors return True; else -- There was no candidate operation, so report it as an error -- in the caller: Analyze_Selected_Component. return False; end if; end Try_Object_Operation; --------- -- wpo -- --------- procedure wpo (T : Entity_Id) is Op : Entity_Id; E : Elmt_Id; begin if not Is_Tagged_Type (T) then return; end if; E := First_Elmt (Primitive_Operations (Base_Type (T))); while Present (E) loop Op := Node (E); Write_Int (Int (Op)); Write_Str (" === "); Write_Name (Chars (Op)); Write_Str (" in "); Write_Name (Chars (Scope (Op))); Next_Elmt (E); Write_Eol; end loop; end wpo; end Sem_Ch4;
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